Chris Bolhuis: [00:00:00] That was a good one,

Dr. Jesse Reimink: that was a good one. Oh, Chris, you are actually doing this all along. You, you are carrying it. Are you, are your shoulders tired from carrying the weight of this Yellowstone course on your backs?

Chris Bolhuis: My shoulders are always tired. I carry my marriage, I carry this course. I carry the entire teaching profession.

Dr. Jesse Reimink: You do. I mean, it's amazing how productive you manage to be [00:00:30] while being in charge of literally the entire world. It's unbelievable.

Chris Bolhuis: I know. I know, I know. Just make me king.

Dr. Jesse Reimink: Okay. Chris. Okay. This is a great chapter and let me tell you why I'm excited about this. I think that this chapter and this geological feature combines a couple of my favorite aspects of Geology. Igneous volcanic eruption rocks - rhyolite, and really kind of catastrophic, like singularly catastrophic events that happen and create [00:01:00] amazing features on earth. And these are actually pretty common in the rock record. And so that's why I'm excited about this, is we get to combine these two really cool topics.

Chris Bolhuis: Because today we are talking all about the Grand Canyon of the Yellowstone River. Now Jesse, I gotta tell you, I've been here more times than I can count. I swear, when I was a kid, I thought that this was the Grand Canyon. Okay. I, I did, I, I, you know, Hey, Chris, have you ever been to the Grand Canyon? Yeah, [00:01:30] man, every summer I go there. Don't you know it's in Yellowstone.

Dr. Jesse Reimink: You know what? It's very funny, the visual I have is little baldheaded nine year old Chris Bolhuis running around being like, yeah, I went to the Grand Canyon. And that would be really funny to me. Except I think that was the same because the summer science trip that you lead every summer high school students out West Yellowstone, you spend about a week there with, you know, 25 high schoolers and you're teaching Geology in Yellowstone. And my dad taught it. So as a little kid, I kind of went along on this trip too, [00:02:00] and I did the exact same thing. I was convinced that this was the largest valley I'd ever seen and that ever existed in the world in that this was the Grand Canyon.

Chris Bolhuis: Because, because it's amazing. It is absolutely amazing!

Dr. Jesse Reimink: It is totally

Chris Bolhuis: So let's get down to business. Jesse, let's jump into the Grand Canyon of the Yellowstone River. And image number one in your stack does, I think, just a great job of showing, maybe one of the most beautiful aspects of the canyon. You can see how deep it is. [00:02:30] You can see how wide it is. You can see the colors, you can see the Rhyolite, it's really got everything. The lower falls are kind of there in the background. It's awesome.

Dr. Jesse Reimink: You're exactly right Chris. It shows the whole story right here, and we're gonna talk our way through this story, right? We're gonna start on, kind of some statistics of the, of the canyon. Kind of describe it. We're gonna get into the Geology, the rocks. Why are the rocks there? We're gonna get into the canyon, cutting the canyon through the rocks, why there's waterfalls in there. And and we will end with really you giving us some pointers [00:03:00] about where to go to best see the Grand Canyon of the Yellowstone and see the geological features that we're talking about right now.

Chris Bolhuis: I'll do my best that in that, because you have to curate all this stuff. There are so many options in this, and so we're giving a very curated version of tips and pointers of both hiking, driving and turnouts and, things like this to maybe don't misses, right?

Dr. Jesse Reimink: And so Chris, let's just start with bit of an overview and we'll point to image number two in your stack, which is just a gif that highlights exactly [00:03:30] where. The Grand Canyon of the Yellowstone is what we're talking about right now. And this is a, a big feature. I mean, it is a dramatic feature on the landscape. It's about 20 miles long or over 20 miles long. There's two huge waterfalls. Both of them spectacularly beautiful and quite different. The canyon averages over a thousand feet deep. That's on average through the length of this 20 miles. So that's a huge, huge feature. And it's between 1500 and 4,000 feet wide. It is a big big feature that you [00:04:00] can see.

Chris Bolhuis: The two featured waterfalls, the, they're very aptly named the upper and lower falls. The upper falls, the water drops 109 feet and the lower falls, which are my favorite, they drop 308 feet. And all of this happens, as you said, right from the get go. This happens in the rock Rhyolite. This comes from a lava flow that is 480,000 years old. Jesse, let's jump into [00:04:30] a little bit of the Geology. Let's shift gears a little bit and get into some specifics. The details.

Dr. Jesse Reimink: This is the fun part, right? We're gonna start kind of gonna start big and zoom in again. The Yellowstone River. This is a really interesting thing. I did not actually know this until we started putting this together, or I'd probably forgotten it. I mean, I've learned it from you when I was on the summer science trip in high school, but that was a bit of a longer time ago then than I'd like to remember. But,

Chris Bolhuis: You don't remember every single word I said?

Dr. Jesse Reimink: No, it's surprising Chris, it, it's very surprising. The Yellowstone River [00:05:00] is actually the longest Undammed River in the contiguous United States - 600 miles long. And it drains out of the northern end of Yellowstone Lake. So this is image number three, shows and highlights where the Yellowstone River is, but it drains the northern end, so the river's flowing north. We touched on this before. The river is flowing up. In your map view, which is confusing to those of us who sometimes struggle with up and down on maps as we talked about before, Chris.

Chris Bolhuis: That's right cuz remember, water does not flow uphill. [00:05:30] Therefore water can't flow north.

Dr. Jesse Reimink: Right. Yeah, exactly. Commonly known. It's, it's, everybody knows that. Right. Um, and the really, this is the interesting part, Right. When you're near Yellowstone Lake, and this is the, area between fishing Bridge and Canyon, when it's called Canyon and is the Grand Canyon Yellowstone. The river's pretty calm and meandering. You would not expect there expect there to be these really massive waterfalls downstream when you're right by the lake, right When you're by Yellowstone Lake. I mean, you can see, you talked about it before Chris. You can see some of the cutthroat trout swimming in the [00:06:00] stream if you're lucky enough. And it's really calm, peaceful water, right? Like what's going on there?

Chris Bolhuis: It, it really is calm. There is a notable exception that I want to get to first. It's called La Hardy's Rapids and it's north of Fishing Bridge. It's the one exception in this stretch of river where you actually have significant white water. And I wanna talk a little bit about what's going on with this, because I think it's important. These rapids, they result from a series of these step like extensional faults, [00:06:30] where the faults are a result of the rock being pulled apart. The cause of this is a resurgent dome. This bulging up. And if you think about it, if you take rock and bulge it up from below, that's gonna cause it to extend at the surface and kind of pull apart. It's like, um, what happens to your skin when you make a fist? You know, the skin around your knuckles get stretched. And if you have really dry skin or brittle rock, it can't just stretch like that, it'll split. Right. So [00:07:00] is that a crude analogy?

Dr. Jesse Reimink: I, no, it's uh, I mean you've been using this one since, I think when I took the first class from you in 2001. You used it then, and it was disgusting analogy then, and it remains kind of a gross analogy, but you've used another one where Your fist punching up through, a bread loaf or something like that, you know, soft bread loaf and you punch up through it and it kind of cracks the top open. Right As the bread dough rises, it cracks that crust or as you punch through it, it rises and cracks the surface. So that's what we're talking about. And those are those [00:07:30] extensional faults you're talking about.

Chris Bolhuis: Exactly. And so the rapids result from falling down these step like extensional faults. so in a sense the rapids are the true northern boundary of Yellowstone Lake because this, this resurgent doming controls how much water is kept in the lake, or how much the lake can drain.

Dr. Jesse Reimink: Okay, Chris, I'm gonna interrupt you real quick there because I'm gonna make one point and then I want you to explain that cuz I didn't quite follow [00:08:00] that line of reasoning. But first I wanna make the point that you just said that the river, the, rapids are a geological feature of extensional faults. And this is so common in Geology and it frustrates me that people don't recognize this, like at default is that almost every feature, like a little bit of a rapids or riffles in a river, that's there because of the Geology, like the underlying geology's changing, something's changing in the river and it's the Geology that's changing that does that. I mean, I experience this in Pennsylvania all the time. There's little riffles and it's [00:08:30] because there's a big sandstone lens in the river right there, and it's more resistant. So anyway, That's my rant, but I don't quite follow what you're saying with the northern extension of the lake. Can you elaborate on that a little bit?

Chris Bolhuis: Yes. So north of Yellowstone Lake, where the shoreline is right now, you have this resurgent dome, and if the dome inflates. Then water is kept in the lake, And so the, the lake will creep up and creep up and creep up. If the dome deflates water is [00:09:00] let to drain out of the lake, down the Yellowstone River, and then eventually into the Grand Canyon of the Yellowstone.

Dr. Jesse Reimink: Okay, that makes complete sense. Yes. So this do, this resurgent dome, when it kind of swells up, it kind of blocks the river a little bit more and holds more water to the south in the lake. When it sort of, calms back down the river can flow to the north and more water can flow. That makes complete sense. Thank you.

Chris Bolhuis: It’s kinda like taking a deep breath on how your chest heaves, and that's what the resurgent dome does when it inflates. And then when you exhale and you blow the air out, your chest [00:09:30] deflates. And that's what happens. The resurgent dome, it kind of huffs and puffs, and it does this naturally because of what's going on underneath. This is a very restless, geologic feature that we have going on.

Dr. Jesse Reimink: Totally, So Chris, then after, as we move further to the north downstream, just south of Canyon Junction, the river really dramatically changes personality. And this is the meat and potatoes of this chapter. This is where we move into the Grand Canyon of the Yellowstone, and the change is [00:10:00] dramatic because the underlying geological change is quite dramatic. And we're gonna start to touch on this. We said this before the canyon cuts through. We're gonna talk first about the rock around it. What is the canyon cutting through? And then we're gonna talk about the cutting of the canyon. Those are two separate things. First, it cuts through Rhyolite. Chris, you and I have seen a ton of rhyolite together, including rhyolite here in Yellowstone. We've collected rhyolite, importantly, not in Yellowstone National Park in other places. Safe to say we love rhyolite. Is that a fair statement?

Chris Bolhuis: [00:10:30] Oh, that is more than a fair statement because whenever you handle the rock Rhyolite, you're handling something that is geologically very, very powerful. Rhyolite comes from this really sticky kind of magma that became lava and that kind of stuff is indicative of potentially very explosive volcanism that you get with Yellowstone, right? So, Rhyolite is this, Really light colored. extrusive [00:11:00] igneous rock, it's, it's the equivalent of Granite. I think most people are familiar with what Granite looks like, but Granite cools slowly deep beneath the surface. If you take that same composition magma, and bring it up and out onto the surface where it cools much faster, it's very sticky, very viscous kind of stuff. That's what makes up most of the Caldera of Yellowstone National Park, And that's what this canyon has cut through.

Dr. Jesse Reimink: The important part is the sticky part. We touched on this in the, the background Geology [00:11:30] of Yellowstone. The, the sort of overview in chapter one, the mantle plume in chapter two. talked about this before and it is this light color, but it's not necessarily like always white, right? They can have a lot of. Different colors to it, and we'll come back to why that is. But rhyolite can look pink. It can be kind of this, this darker grayish, material. It's rarely black, but it can be pinks and yellows and whites and all sorts of colors in between there.

Chris Bolhuis: Jesse, I want to interrupt you a second, because I want to describe these lava flows. [00:12:00] These are, immense. We're talking about flows that are over 2000 feet thick, you know, so these are massive features, right? And again, we said this before, but to restate it, This lava flow in particular came from an event that happened 480,000 years ago. So, let me put this in perspective. Since the last cataclysmic eruption 631,000 years ago, there have been about, hmm, 20 to 30 of these massive kind of lava [00:12:30] flows and then several dozen smaller ones, that sets the stage for what we're talking about here.

Dr. Jesse Reimink: And I think it's important Chris to note that here at the Canyon we, we can see a cross section through that. So as the canyon cuts down through that, we're seeing a cross section through a big lava flow. We're seeing the guts of it. We're seeing the interior of the lava flow as we're looking down the canyon, looking at the side of the canyon wall.

Chris Bolhuis: So that's the first thing. Rhyolite is key, and this canyon is cut down through the flow. So like you said, [00:13:00] beautifully, we get to see the guts of the lava flow, which is not a common thing. Okay? The second thing, this area is also a geyser basin. No matter what rim you're on, if you're on the south rim or the North Rim, doesn't matter, you can look down into the bottom of the canyon and you can see signs of hydrothermal activity all over the place. You can see fumaroles, you can see water seeping through the canyon walls and down into the river below. So that brings us to this [00:13:30] point that if you've filed it along from chapter to chapter, this should make sense. What does hydrothermal water that is salty and very acidic. What does that kind of stuff do to rock?

Dr. Jesse Reimink: Oh man. How long do I have Chris to to answer this question?

Chris Bolhuis: You don't have long,

Dr. Jesse Reimink: Okay. Alright. Uh, it, it, it eats it away. It basically eats it away. And there's two reasons for this. First of all,

rhyolite is a fine grained rock, [00:14:00] so it is not super well put together necessarily. If you have a Granite where all the crystals are growing and it, it's crystallizing, it's cooling down at depth in the earth, cools down super, super slowly, all those minerals have time to grow and interlock with each other, so it gets really solid. I mean, this is why we make countertops out of this stuff. It's super well put together. Rhyolite, it's rare you have a rhyolite countertop because this is welded together. All these mineral grains and all this little pieces of liquid rock got spewed out into the [00:14:30] atmosphere, and then they were welded together while they were still hot, and it cooled really quickly. There's a lot of gaps. It's a very porous rock typically, so water can flow through there. That's the first thing. The second thing is this is hot and salty and acidic, and therefore reactive water. And when things are hot, chemical reactions happen a lot faster. So the fine grain nature and the hot water means that these reactions, these alteration, and weathering and, and eating away reactions occur really, really quickly in Rhyolite. Much quicker than in other types of rocks.[00:15:00]

Chris Bolhuis: It's making the rock more erodible. It's easier to cut through. The third thing one was Rhyolite. Two, was it's a Geyser Basin - Hydrothermal geyser basin. Three, is there are also faults here. The canyon is very near the rim of the Caldera. And what you had then are these ring fractures and faults that happened as the Caldera sank down in. So we have area that has been hydrothermal altered [00:15:30] and weakened. And then it's also been faulted, which helps to weaken the rock even more. So Jesse, because of this, we really know that there was a canyon that existed here a long time before the present canyon that we get to see today. It just wasn't as wide and it wasn't as deep, but there had to have been. Because…

Dr. Jesse Reimink: Probably right? You know, weak part of the rock, which is easier to erode, and so therefore it's very likely that there was a canyon there before. [00:16:00] And this is really important because as we talked about before, when we were sitting in our 30,000 foot hot air balloon over the area and watching through geological time, we saw the glaciers move in and out. We saw this big ice cap sitting on Yellowstone and glaciers moving around. And Chris. Glaciers just like water follow this path of least resistance. They flow downhill and they flow downhill where it's easiest to flow, which is in weak rock like we're describing here. So now Chris, we're transitioning from what are the rocks to how did we get the valley there?[00:16:30] You've laid out the recipe for weak rock and weak stuff. Why There's weak stuff here. And now we need to make the valley. And Chris, you taught me this when I was in high school. I now teach this to Penn State undergrads in the big lecture hall with the the 250 undergrads I teach every fall. The basics of Geology - glaciers, they carve U-shaped valleys. This is why Yosemite National Park, this is why the Alps, any glaciated terrain is spectacularly stunning, is because they carve U-shaped valleys. [00:17:00] Rivers they carve V’s. If you look at a cross section of the valley - if you look downstream at a cross section, you see a V shape in the Grand Canyon of the Yellowstone, which means it's a river, not a glacier. So I kind of just painted this picture of, oh, there were glaciers, but it's V-shaped valley. So kind of talk us through that geologic story. Maybe Chris, like, how, how do we, like, you know, make the connection here.

Chris Bolhuis: For sure. One is, I'm gonna point to image number four in your stack right now, which is a beautiful image [00:17:30] of an erratic boulder on the rim of the Grand Canyon. It's enormous. You can see this, massive boulder with lodge pole pines growing.

Dr. Jesse Reimink: I mean, that’s huge!

Chris Bolhuis: It is. There should be a person there for scale. Okay. There, there should be some awkwardly standing person there for

Dr. Jesse Reimink: Oh, conveniently, there is an awkwardly standing person there for scale. It's great.

Chris Bolhuis: Oh, there is, there is. Yeah. Okay. All right. I, yeah, I see the person now. Boy, [00:18:00] that is a huge rock. Anyway, this boulder could only have gotten there by riding piggyback style on or within a glacier. And then when the ice melts, it just drops these things off indiscriminately

Dr. Jesse Reimink: There's no way water can move that boulder. It's far too big for a massive stream, even at flood stage to carry that thing. It's gotta be glacial ice.

Chris Bolhuis: But a glacier doesn't care. A glacier can carry a rock like this as easily as it can carry a grain of sand, and so when it melts, then it just plops it off [00:18:30] wherever it happens to be. We have these all over the place along the rim of the Grand Canyon, so we know that there were glaciers that were scouring the Grand Canyon, but we know that it wasn't as wide and as deep as it is today because of the shape of the Canyon. It's not a U, so the U would've been not quite as wide and certainly not quite as deep. We still need to move into the final story and the formation of the canyon as we see it today, to make it as wide and as deep as [00:19:00] we have. But there's abundant evidence that glaciers moved through this canyon before the water did what it did.

Dr. Jesse Reimink: Definitely. And Chris, this is my, my favorite part of this episode. I mean, I love Rhyolite and I love the hydrothermal alteration, but this is the more exciting part I think of this story because it is this sort of cataclysmic event. And in Geology we often talk about how, you know, really slow movements end up over a long period of time really having this dramatic effect. Plate tectonics, you know, slowly plates are [00:19:30] moving, at the rate your fingernail grows and over millions of years that equals a lot of motion. Uh, this is different. This is a lot of stuff happens really quickly. This is a traumatic event and really what we're talking about is glacial floods. And so around 14,000 years ago, we talked about this before in our 30,000 foot hot air balloon, we could see the glaciers are retreating. The ice would've created a dam, and the dam would impound Yellowstone Lake. So the lake would [00:20:00] kind of back up behind this dam. And we talked about if we're trying to build a dam, you would not build it out of ice necessarily. That's not the best dam material because ice breaks. And Yellowstone Lake, as we've talked about before, was much bigger. All of Hayden Valley would've been underwater. When these ice dams broke and they broke multiple times, a massive, massive amount of water would start flowing downstream to the north through what is now the Grand Canyon of the Yellowstone. And all that water [00:20:30] at flood stage ripping down the valley would just cut through this super soft weathered altered faulted rhyolite that we set the stage for before.

Chris Bolhuis: And those ice dams would've formed and broken many, many times. But the point is, is that this canyon did not take millennia to form. This canyon formed in weeks or months, not thousands of years as we typically have in Geology. This didn't happen, one grain of [00:21:00] Rhyolite at a time. This happened. These were biblical events to say the least.

Dr. Jesse Reimink: definitely. Uh, this is just such a cool thing to think about. I think Chris, like, you know, the fact that the Grand Canyon in Arizona, the Grand Canyon National Park - that takes a long time, millions of years to cut that deep canyon. This is a different beast. This is cutting through really soft rock, really rapidly with these catastrophic ice dam release floods.

Chris Bolhuis: So can I interrupt you a second? If you can envision this going on, these ice dams forming and [00:21:30] then breaking and forming and breaking. Something really dramatic happened at the brink of the upper and lower falls, and I wanted to turn you to image five here a second. This image shows what we call the brink of the lower falls, which are the, bigger in, in my opinion, the more spectacular of the two. In the park, they use the term brink for the waterfalls often, and in Geology we don't use that term very much. Uh, in fact I've [00:22:00] never heard it before. Really? Outside of Yellowstone. Have you? Have you ever heard that before?

Dr. Jesse Reimink: No, no. I mean it's more of like, you know, oh, don't walk to the brink or the edge. Right. We use Nick-Point is the term that, I'm familiar with and I'm, sure the term that you're, speaking about here, right Chris? Because we gotta talk about the waterfalls cuz We painted this picture of this massive flood, you know, going down the river valley, which should just cut kind of a straight line, you would imagine. But there's waterfalls in there, like what the heck's going on with these waterfalls. So the brink or nick-point, as we call in Geology, [00:22:30] what's going on with this Chris?

Chris Bolhuis: During most of the stretch the Yellowstone River from Fishing bridge to, just south of Canyon Junction, the river is flowing over really hard solidified, well put together lava. At the brink or the nick-point of the upper falls, something dramatic happens there where as it down cuts and down cuts and down cuts, because that's what rivers do. It down cut into [00:23:00] hydrothermally altered Rhyolite. I use the analogy, Jesse, and I don't know if this works or not. You can let me know. I'm sure you will. It's kind of like,

Dr. Jesse Reimink: I'll tell you.

Chris Bolhuis: Yeah, I know you will. It's kind of like a baked potato. What I mean is, that you go from really hard Rhyolite to the baked potato is the hydrothermally altered rock. The stuff that's much easier to scoop out like a baked potato is. Does that make sense?

Dr. Jesse Reimink: So the, [00:23:30] the rhyolite is the outer skin of the baked potato. Is that, is that it?

Chris Bolhuis: No, no. Jesse like, ah, no! It's like comparing a regular non baked potato to a baked potato. Okay. So, When the water cuts down through the non baked potato, it's very, that's a monotonous process. That's not gonna happen fast. And then it gets into this softer, chewed up kind of, easily eroded rock. And it starts down [00:24:00] cut that much easier. That point right there when you go from hard rock to softer, hydrothermally, altered rock, that's the brink or that's the nick-point right there. And that's the upper falls. And then it continues. Oh, go ahead.

Dr. Jesse Reimink: You know, the way to think about this is it soft rock, you can cut quicker. So of course once you hit soft rock, the water level is gonna drop lower. The river's gonna cut deeper, quicker, which is going to juxtapose hard rock, which is higher up in the river [00:24:30] system and soft rock, which is a lot lower down now you've got a waterfall right in between those two because all of a sudden you've got an elevation difference because the river, the same energy of water flow can cut quicker through the soft stuff. So it just cuts down a lot faster. And so that's really kind of what's going on. And this is a very, You know, classic Nick-Point, example, hard rock, soft rock. There's a waterfall right there at that boundary. Again, the Geology explains what's going on all the time. Uh, but anyway, sorry Chris, I interrupted you there.

Chris Bolhuis: No, that's okay. [00:25:00] So then as you progress further downstream from the upper falls, the same kind of thing happens. It goes to a softer potato, if you will, As it cuts down deeper and deeper and deeper, it gets to this really hydrothermally altered stuff, which is very soft and faulted. Don't forget about the faulting, right? And so this rock is just easy to chew up. And so you have now the brink or the nick-point of the lower falls. And that's more dramatic because that rock [00:25:30] down there is really, really quite soft. And so there's a dramatic difference.

Dr. Jesse Reimink: Chris. Yeah, that's a great point. and this leads really, really nicely into our next thing we have to talk about, which is the colors there. But just to reiterate, the upper falls are named the upper falls because they're upstream. The lower falls, which are the more spectacular ones, are downstream. So that's the difference between upper and lower there. But we have to talk about this really weak, really crappy, really altered, really faulted rock down in the lower falls [00:26:00] below the lower falls downstream of the lower falls. This is really spectacular rock actually. It is so beautifully colored. And we can point to image number six here, which shows this, but you can see this in the walls of the canyon everywhere. These are yellows and oranges and pinks and lavenders and every shade in between all of these whites and grays. It's beautiful, beautiful, beautiful rock to look at. And the colors are really part of this hydrothermal alteration process. The [00:26:30] alteration is the colors. And different alteration gives us different colors. Give us a brief intro, Chris, about what is going on here?

Chris Bolhuis: I think that's a really good point. First of all, Jesse, that the colors explain why the canyon's here. The colors are from hydrothermal alteration. Hydrothermal alteration is why the rock is so soft. And then it's also faulted, which is again, why the canyon's here.

Dr. Jesse Reimink: Let me interrupt, uh, Chris real quick because I think that that's a really good point you just made. And I just thought of this like I, most people, and I think I thought of this for a long time [00:27:00] too, when you look at those like colors and the streaks in the canyon wall, it kind of looks like just surface coloration. It looks like somebody took a crayon and just draw on the side. But actually no, that's not right. If you cut into the side of the canyon, it's going to be colored as well. That is color that permeates into the canyon wall through the rock, and that's why the canyon's there. That was beautifully put. I just wanted to underline that because that was really beautifully put.

Chris Bolhuis: Oh shucks. Jesse, thank you. That's so nice of you to say. Yeah, thanks. Um, alright. So the colors, the colors result[00:27:30] from various stages of oxidation. So this Rhyolite has iron and iron compounds in it. And iron oxidizes or, we call it oxidation and chemistry, and the people call it just rust. So iron rusts, and dependent upon the type and degree of oxidation, you get just different colors. You get the yellows and the reds and the lavenders. And a lot of people look at this, and they look at all [00:28:00] the, the yellows and they smell the H2S, cuz you certainly can smell this in certain areas around the Grand Canyon of the Yellowstone also. And they think it's sulfur. No, not here. The yellows and all of the other colors for that matter, are primarily a result of iron oxidation in various states of that.

Dr. Jesse Reimink: Yeah. And the yellow actually is a really interesting one. I mean, it's a, it's called Goethite, or Goethite is the, one of the mineral names in, they're one of these that makes this yellow color, and it's actually hydroxide too, so it's like, rusted iron [00:28:30] that also has a water attached to it. So it's, it's hydrated, it's oxidized. This is like, signature of super, super altered rocks. So this stuff has been hosed with hydrothermal fluids, and it's beautiful. Makes for beautiful rocks. So I think Chris, does that cover the geological story of the Grand Canyon of the Yellowstone here?

Chris Bolhuis: Well, I think it does, Jesse, because I think I understand it perfectly, so…

Dr. Jesse Reimink: Okay. Well I think I get it too. [00:29:00] Yeah, it's good enough for me. I think, Chris, how about we do this? Why don't we, you've been there a lot, and as you said, you've been there more times than you can count. You've run this trip where you're actually teaching high schoolers, So you've done, I would say, hard field trip leading here in Yellowstone for a long time.

Chris Bolhuis: Yeah, I don't know. They're pretty awesome. I'm gonna just say it. They're, they're pretty

Dr. Jesse Reimink: Okay. All right. Fair enough, fair enough. But. Chris, I'd like to just sort of have you guide us through the North and South [00:29:30] Rim, cuz there's kind of two ways to approach going to and visiting the Grand Canyon Yellowstone. So, let's work through North Room, south Rim and let's work through driving recommendations in a few hiking recommendations to just guide people are listening to this and give them some tidbits of wisdom from Chris Bolhuis.

Chris Bolhuis: Quick interruption. Just wanna say to stop at Canyon Village and get a map. Get a map of the Canyon area. It's too big. It's too broad for us to provide that in this kind of context and setting.

Dr. Jesse Reimink: That's a great point. Chris, [00:30:00] we talked about what should we add a map in here? It's just not like, go get one. The paper one's better, the rangers know it. They'll give you more up-to-date information about what's open, closed, et cetera. Like what, what's good, what's not good. So, you know, ask the Rangers as well. Let's start with the North room. Is that good? Chris North Room driving directions or driving suggestions here? What do you think?

Chris Bolhuis: Well, north Rim Drive, so we're talking about the North Rim. This is a one way drive. I think all of the turnouts and stops are worthwhile, as you enter Northrim [00:30:30] Drive. Cuz like I said, it's a one-way drive. The first stop is gonna be the brink, which again, we already talked about. That's the nick-point of the lower falls. So it takes you, you know, you're not gonna see the upper falls in this area here. It's gonna take you right downstream to the brink of the lower falls. From there, you can drive to Lookout Point, you can drive to Grand View, and finally you can drive to inspiration point.

Dr. Jesse Reimink: Yeah.

Chris Bolhuis: um, which are, I think all highly, highly recommended.

Dr. Jesse Reimink: [00:31:00] so good.

Chris Bolhuis: So then this road is gonna take you right out by Canyon Village. And then, of my favorite things to do is, oh, hey

look, we're by Canyon Village, let's go get some ice cream. It's a great place. Okay. Seriously.

Dr. Jesse Reimink: I, Hey, I do. I love a good bit of ice cream. That's a good suggestion. A key. Don't miss that.

Chris Bolhuis: That's right. So you can do some gift shopping right there. Get some ice cream. And there you go. You just did the Northrim Drive and it's amazing. So I highly recommend it.

Dr. Jesse Reimink: That's a good one. So, hiking recommendations, you know, a lot of these stops have hiking trailheads. [00:31:30] Any suggestions in maybe, you know, various skill levels or various difficulty levels, depending on how people are feeling that day?

Chris Bolhuis: Yeah, I wanna try to kind of spread it out a little bit so that, people can kind of gauge their do it all or do some of it. That's kind of my thought process in this. The first recommendation, North Room Trail, it's a three mile one way trail, but you can do it in sections. What I mean is, you pull off at the trailhead there and you hike a little bit of [00:32:00] it. And you see what you want to see, and then you walk right back to your car and you drive to the next place and you hike a little bit and you keep doing it this way and you can make your way down most of, or the entire North Room trail. In terms of like flat-out hikes or, or walks, I'm gonna start with the hard recommendation. When you enter Northrim Drive, your first opportunity to hike is gonna be the brink of the lower falls - the nick-point of the lower falls. [00:32:30] This would be my best recommendation on this side of the canyon. It's steep though, so it's not for everybody, and you need to understand that. It's 0.7 miles long. At the end of it, cuz you, you walk down right? And then at the, that's easy at the end, you gotta walk all the way back up. You have to ascend over 600 feet at the end of the hike. But to me it's worth it to see just the raw power of Geology. To see the raw power of the lower falls.

Dr. Jesse Reimink: [00:33:00] This is really funny, Chris. I mean, a classic, thing when you're looking or visiting a canyon and you have to go down first and then back up at the end. It's horrible. I mean, we both grew up in Michigan and there's this one place in Michigan where big, big, big sand dune. I mean, there must be 400 foot sand dune, and you'd just sprint down it and you'd hit the lake at the bottom and you'd be like, you'd turn around and you'd look up and you'd be like, Oh, what have I done? I have to go back up. And so, this is one of those classic conundrums here, so, okay. That's a good, hard one.

Chris Bolhuis: Hold on. [00:33:30] It's kind of like collecting firewood on a hillside, right? You always walk up to collect the firewood so that you walk down with your arm load.

Dr. Jesse Reimink: With Yes. Or rocks for instance, I think I've seen you

Chris Bolhuis: Yeah. There you go.

Dr. Jesse Reimink: boulder uphill to the truck before, but no comment.

Chris Bolhuis: It's true.

Dr. Jesse Reimink: Moderate or intermediate.

Chris Bolhuis: My recommendation. Red Rock Point. It's mostly boardwalk. It's 0.6 miles and you have to ascend 260 feet. So it's less than half of the previous recommendation that I made, but again, it offers really, really [00:34:00] great views of the lower falls. And then finally, the easy one - lookout point. This is the easiest and most accessible place for anybody. And to me, I also, I think that if you're there, I don't care what your athletic ability or conditioning is, you should go to lookout point. It's just, it's, it's awesome. It's amazing. It can get busy, so it's not for everybody either. But yeah.

Dr. Jesse Reimink: Okay. Chris, south Rim. Driving Recs on the South Rim.

Chris Bolhuis: Uh, this is a [00:34:30] two-way road, so it's different from the North Room Drive. And it has two main parking lots and this one gets crazy. So if you're driving a big rv, think about this. You will be able to make your way through there. You will be able to turn around. Um, some of it might be a little bit of white knuckle driving. You know, it can get very busy, so, go in the early morning maybe if you can, if that's an option. It's a good option. Both of the parking areas I think are [00:35:00] worth getting out and taking a look. The first one is Uncle Tom's Point. For the first time, you'll get a good view of the upper falls, um, from the Canyon overlook viewing area. At the second parking area,

further down the road, you'll get awesome views of the lower falls, the colors of the canyon, Artist Point to, you know, that. So it's, these are areas that you can

Dr. Jesse Reimink: Totally beautiful.

Chris Bolhuis: that, that, that's the one that is really, really busy. [00:35:30] Okay. The first parking area is not nearly as busy. The second one is almost always busy,

Dr. Jesse Reimink: Okay, cool. And then, uh, for the hikers out there, and let's go again from like sort of harder to easier generally.

Chris Bolhuis: Okay, I'll do my best. So, uncle Tom's trail, and this is taken from the first parking area. It's 0.6 miles total. It's an out and back. So 0.3 out; 0.3 back. It's, I'd say a moderate hike. It's got over 300 steps in it, about 500 feet of ascent in [00:36:00] it. But it offers really, really good views of the lower falls.

Dr. Jesse Reimink: Yeah, it's a beautiful, beautiful spot to lower falls too. Oh, so beautiful.

Chris Bolhuis: Now this might seem counterintuitive, but point sublime. This is an option for people that wanna escape the masses. You're gonna have to park with the masses and then you can kind of get away. It's a moderate three mile hike. This is not very steep. It's kind of undulating, you know, up and down a little bit. Generally flat three mile hike from artist point[00:36:30] out and back. You hike away from the falls, but it gives you spectacular views of the canyon. And it's gonna then give you views that most people don't see. Because to be quite honest, most people that visit Yellowstone are not willing to leave those boardwalk areas and walk great distance. So you'll have some alone time, if you will. I think.

Dr. Jesse Reimink: Perfect. okay. Let's say for those people listening who have one day where they can go to the [00:37:00]

Grand Canyon Yellowstone North Rim or South Rim, what's your go-to?

Chris Bolhuis: boy, that's a really, I,...

Dr. Jesse Reimink: You gotta answer. You can't have the - I can't pick between my kids out here. No. Answer! Which one?

Chris Bolhuis: okay. alright, I'm gonna go. I'm - this is a very hard question for me. I, I'd pick the South Rim and here's my reason why, because you get to see both the upper and the lower falls and you get to see them from fairly close up. And I think that they're both different enough [00:37:30] that. That's a re just a really good option. You're there. Why not? That's my thought on it. So, and also on the south rim, you get to go to Artist’s Point, and that's just the, that's the easiest of my hiking recommendations. It's a five minute tops, walk from the parking area and it's all flat, very super easy. So yeah, I guess that's where I go.

Dr. Jesse Reimink: Okay, cool.

Chris Bolhuis: Jesse, that brings us to the point in this chapter, the FAQs. And I'm gonna flip this to you, so first of all, let's [00:38:00] deal with, um, not really an faq, but just an interesting side note about Artist Point. Is that misnamed? Can you talk about that a second?

Dr. Jesse Reimink: Yeah, so this is a good one. And we talked about how, you know, Thomas Moran, this, this famous, uh, painter who painted these amazing landscapes, you know, and kind of really got the eastern part of the United States really interested in the West and interested in the beauty of the West. And Artist’s Point was originally named Artist Point in 1883. Who kind of thought that that was the point that inspired Thomas Moran, the [00:38:30] artist. Right. Makes sense to name it that way This is actually not true. Basically the name stuck, but his work and his artwork and many of his beautiful framings and paintings were probably done at other locations - not Artist Point. Although Artist Point is beautiful and should be, as you said, visited for sure, cuz it's spectacular. And you could easily paint a beautiful painting there, but probably not one of the ones that Thomas Moran's famous paintings came from. So good one.

Chris Bolhuis: All right. First FAQ. Can one get to the [00:39:00] bottom of the canyon.

Dr. Jesse Reimink: Oh, this is a good one. Remember our, if you want to go down, you gotta come back up thing. Yes, you can actually. There's only one trail that leads to the bottom of the canyon and it's the seven mile hole trail. It's pretty strenuous. It's steep and it's about 10 miles, 10.2 miles. So this is kind of a, you know, I, I would definitely put this into you gotta know what you're getting into before you tackle this one. For sure. Chris, you've done this hike?

Chris Bolhuis: No, I have not. But if you're gonna do this hike, bring water, there will not be an [00:39:30] option to, to get water anywhere along that area. So bring water with you on this and just be prepared to take your time.

Dr. Jesse Reimink: And, you know, check in with rangers before tackling something of this scale. So yes, you can get down there. It's pretty difficult though.

Chris Bolhuis: All right. Good. Last FAQ, Dr. Reimink. How much water goes over the falls?

Dr. Jesse Reimink: This is a great one. And I love these types of questions cuz you look at those falls and they're just massive, right? So the volume varies dramatically as you'd imagine. When [00:40:00] there's snow melt and the water is raging, the river's full, it's really high. It is 63,500 gallons per second. And that is 240,000 liters per second going over the falls. That's a number. It's like saying a trillion dollars. I have really no idea what that means. You know what I mean? Chris,

Chris Bolhuis: It is, it's too big to imagine. It's just a lot of water,

Dr. Jesse Reimink: It's so much, and that drops during, you know, in the, in the dry season, near the end, in late fall. [00:40:30] It can drop down to 5,000 gallons or round about 19,000 liters again per second. So that, that's still a ton of water, but far less than 240,000 liters compared to 19,000 liters per second. So a huge variation. I don't think the falls change that much in beauty though. Really like, I don't think they are dramatically different across seasons. They definitely look different. You can see the water difference, but they're stunning no matter what season you go there.

Chris Bolhuis: It is one of my great regrets actually, that I, [00:41:00] can't say for sure if the beauty is different because, I'm locked in, I'm not allowed to go to Yellowstone in the fall or the late fall because of my day job. It's something that I really, really want to see. I want to see Yellowstone in the fall.

Dr. Jesse Reimink: Chris, just

Dr. Jesse Reimink: Hurry up and retire, man. Just do it, you know. Get, get older quicker. Will ya? I mean, geez.

Chris Bolhuis: yeah. All right. All right. I don't know if I can do that, but Okay.

Dr. Jesse Reimink: No. Alright. Hey, that is a wrap on the Grand Canyon of the Yellowstone. [00:41:30] What of the, the really

more fun geological stories in Yellowstone National Park. What do we got coming up next?

Chris Bolhuis: We have Yellowstone Lake coming up next. The Geology of Yellowstone Lake. Yes,

Dr. Jesse Reimink: Just keep on coming. Love it.

Chris Bolhuis: Right on.

Dr. Jesse Reimink: All

Chris Bolhuis: All right. Well, Jesse, that's a wrap.

Dr. Jesse Reimink: Peace.

Chris Bolhuis: Cheers.