Wanderlist: Surprising Geology

Wanderlist: Surprising Geology

Season 3 Episode 3

Devil's Sinkhole Descent


[SPONSOR] Under the Texas Sky is Brought to you in part by Toyota, a proud supporter of Texas Parks and Wildlife Programs. Toyota, Let’s Go Places.


[NARRATION] Texas has a vast geographic diversity with some of the most incredible scenic landscapes and natural wonders that are down-right fascinating to behold.

On the Wanderlist, Texas Parks & Wildlife Magazine Editor Louie Bond and I will discuss these geological oddities and where they can be found in our state. We’ll also share some of listener’s answers to our latest Instagram question: What’s the strangest natural formation in Texas? Some of the revelations are sure to surprise you.

Stay with us.


[NARRATION] From Texas Parks and Wildlife, this is Under the Texas Sky’s Wanderlist. I’m Randall Maxwell, and joining me by phone from her farm in Wimberley, Texas, is Texas Parks and Wildlife Magazine Editor, Louie Bond.


[RANDALL] How are you doin’ Louie?

[LOUIE] It’s goin’ great Randall. Just me and the chickens. The hens are busy laying eggs this morning.

[RANDALL] Fantastic, I love it. Well, you know this Wanderlist is all about surprising geology. What have you got for us?

[LOUIE] Well you know Randall, this Wanderlist really rocks. (laughs) Actually this Wanderlist ran back in 2019, it is kind of one of my favorites. Because geological oddities are just all over Texas and they are really some of those things that you remember about visiting state parks and other great natural spots, because they’re just so weird and huge, and epically old. And they just really stick with you.

[RANDALL] Well you know we did ask on Instagram last week of all our listeners, what was the strangest formation that they could tell us and well several people spoke up, steph_stiles, kellypodz Hoodoos, laurensweat, barbranned, all about Palo Duro Canyon State Park.

[LOUIE] Yeah Randall, we had so many responses from IG that we can’t mention everybody, but those were some really great listeners who pointed my favorite park, Palo Duro Canyon State Park, and in particular the Hoodoos, one of my favorite words for just about anything, much less a geological formation. Palo Duro Canyon, when you’re driving, you go from Amarillo out to Canyon, Texas, and then you go on out the road to the park, and you’re just driving along that flat Panhandle land, and all of a sudden it just drops out, and this canyon, and I mean it’s second only to the Grand Canyon in the whole country, just appears before you. And it is just a huge lesson in geology. It’s candy-layered formation, so there’s ribbons of striated rock that are just gorgeous colors of pinks and oranges. It’s all formed of course by erosive action, and that erosion happened with the Prairie Dog Town Fork of the Red River over 90 million years ago. So that’s a long time, and it exposes these beautiful rocks. The canyon is 120 miles long, and Palo Duro itself means hard wood or hard stick in Spanish and that totally comes from the Mesquite trees that grow there. That actually some ancient people lived on those Mesquite beans.

[RANDALL] You know, I’ve seen those beans hanging from those trees, and I’ve always wondered if you could eat those.

[LOUIE] Well apparently the people who lived there 12 thousand years ago did learn how to live on those. Those are the Clovis and Folsom people you hear a lot about Clovis points and Folsom points if you’re an arrowhead hound in Texas. And they first lived in the canyon and hunted those large herds of mammoth and giant bison that lived there. After them, other cultures like the Apache, Comanche, and Kiowa used the canyon’s resources to survive. There were even major historical battles in the canyon, including most famously the Battle of Palo Duro, which was a famous battle of the Red River War between the U.S. Army and the Southern Plains Indian, and that was back in 1874. So what draws people to Palo Duro besides those beautiful candy-ribbon rocks, are the caves and the Hoodoos. And you all know what caves are, but Hoodoos are, it’s just such a great word, and they are actually tall thin spires of rock. They look like totem pole shaped figures like bodies, and they range from human size to many stories tall. One of the best known and major features of the canyon is the Lighthouse Rock. You can see it from everywhere in the park just about. And there’s a multi-use, 6-mile round trip, loop trail to go to the formation itself. One really famous artist spent some time there, the painter Georgia O’Keeffe. She lived in Amarillo and Canyon in the early 20th Century, and this is what she wrote about Palo Duro, which she painted extensively at that time: “It is a burning, seething cauldron, filled with dramatic light and color.” So she was really inspired by the canyon, and in fact, taught at the college there in Canyon, which back then was called West Texas State Normal College, and is now West Texas A&M University.

[RANDALL] Well I’m curious what the abnormal college would be. (laughs)

[LOUIE] That’s right. I’m not sure they would let us in the normal college Randall. (laughs) I’m not sure why they let Georgia O’Keeffe in there. (laughs)

[RANDALL] Well it certainly is a cauldron of blending colors. I’m just so fascinated every time go up there and see Palo Duro. It is so red and like you said, that candy-ribbon. It really is a beautiful sight.

[LOUIE] And you know it’s really filled with wildlife. I remember hiking up there solo a few times and as you hike up there to that Lighthouse formation, there are wild turkeys just along the pathway, just hardly even moving out of your way. So it’s a very rich, yet isolated and solitary experience up there for those who seek that out.

[RANDALL] Well you know Louie, another big entry on Instagram from our listeners was the Balanced Rock at Big Bend National Park. Marissaanne_fitz, batxstate, neeners721, c pressler, they found that are beautiful and it really is, it’s got like this big incredible boulder that, well, you tell me about it.

[LOUIE] Well, you know Big Bend National Park is actually another one of those places like Palo Duro that is just a crazy amount of geology all in one place. I really love this one quote from Walter Prescott Webb in 1937. Here’s how he describes Big Bend National Park’s geology: “Somewhat like the order of a great city built of stone and brick- wrecked by an earthquake. Perhaps order once prevailed there, but some mighty force wrecked the place, shook it down, turned it over, blew it up, and set it afire.” (laughs) “Evidences that all this happened exist on every hand, making the land the finest example of earth-wreckage in Texas.”


[LOUIE] That means it’s got the best geology. And really the balanced rock is just one of the wonderful things out there. Incredible boulders erupt all along this two-mile Grapevine Hills Trail. But at the very end you’ll find the big payoff, which is a boulder balancing act. One enormous boulder balanced atop two others, and it offers kind of a window-like space where a hiker can actually get inside, take a selfie, and also enjoy an incredible view. The trail is really not tough until the very end. It’s mostly wide and sandy, and then you just kind of scramble with your hands and feet over some boulders. Kids will actually love it. Once you’re already out there at Big Bend, it’s well worth it to stay a few extra days and go see some sites like this, you might have to little rough drive and a little rough hike to get there, but it’s really some of the greatest wonders of Texas.

[RANDALL] You know is there any, I don’t know that, is there a chance that that balanced rock might become unbalanced at some point, or is it pretty much lodged there?

[LOUIE] You know we saw on the news I think a few years ago where some mischievous, I have worse words for them, people upset a rock in one of the national parks that had been balanced there and there was such a huge public outcry, yeah I think Texans care about their parks and wouldn’t dream of doing something like that. But I think it would take quite some pushing to dislodge it. It’s been there a long time.

[RANDALL] Well then there’s the Caverns of Sonora.

[LOUIE] You know, it’s one of those things when you’re driving out to Big Bend, you’re on the highway it seems like forever. And when you get to Sonora, you kind of think, well I’m almost there I should just keep going. But you really need a break at that point. And there’s no better place to stop for a break on your way out West than in the glittery and surreal world of the Caverns of Sonora. There’s all kinds of mineral formations underground. And they have these great names. There’s soda straws, which are a type of stalactite, popcorn, which are calcified little nodes that look just like popcorn. And my favorite, bacon.

[RANDALL] Mmmmm.

[LOUIE] Layered carbonate rocks that resemble that familiar breakfast treat, although I eat it all day long myself. The cavern itself is located on a ranch where you can camp and hike, and also gemstone hunt. It’s a really interesting place, halfway between Big Bend and San Antonio as we said. It’s actually on a private ranch. It was discovered 100 years ago when a dog chased a racoon into a 20-inch cave opening. But the full beauty of the caves wasn’t really discovered until some decades later when some geologists kind of hiked around the other side and found another way in, and that led them into so many caverns and tunnels. It’s really one of the most beautiful caverns in the world. It’s actually, unlike some caverns which are cool, this one is pretty warm and extremely humid. And it’s that humidity that keeps all those formations alive. They offer some great tours. The general tours are only a dozen people or so at a time. It’s about two miles and it is filled with formations. There are about 360 steps, just as a warning to those who are a little physically challenged. There are school tours, there are specialty tours for repelling and photography, and the most incredible spot of all the caverns is the Crystal Palace section. It’s 155 feet underground, and there are so many stalactites and stalagmites in varying shades of white and amber. It really looks like a crystal palace underground.

[RANDALL] So they have it lit up down there with lights and everything?

[LOUIE] Yes, yes, it’s just beautiful.

[RANDALL] Wow, definitely worth a stop. Well, you know Louie another fascinating place that I know Parks and Wildlife is very familiar with because it’s a state natural area, and one of our listeners mentioned on Instagram, I believe it was Sabinalriverinvasives, mentioned Devil’s Sinkhole State Natural Area.

[LOUIE] Yeah Randall, we write about Devil’s Sinkhole quite a bit in the magazine, because it’s fascinating on a number of fronts. Of course everybody knows it for the huge bat emergences there. But it’s also just such a neat geographical wonder as well. Native Americans believe that sinkholes were a passage to the underworld. So that adds quite a bit to the mystique and mystery of this 400 foot deep sinkhole. As I said, home to one of the largest colonies of Mexican Freetail Bats, 3 million of them, consume up to 30 tons of beetles and moths each night. So you have to make a reservation to visit, but it’s not hard to do. The state natural area is Northwest of San Antonio in a tiny town called Rock Springs. And there’s a 50-foot wide shaft, drops 140 feet into the cavern which is 320 feet wide, and they don’t allow visitors to enter the cavern. Occasionally they will have a special program where they are doing some studies, and a lucky few will get to repel down into there and I’ve seen some amazing photographs from those expeditions. It’s the largest single chamber cavern and the third deepest in the state. The way it was created was an underground cavity collapsed. So that’s why they call it a sinkhole.

[RANDALL] The Sometimes Islands. Uh, what’s that all about?

[LOUIE] You know, it’s just an intriguing name isn’t it? I mean, sometimes?

[RANDALL] Yeah. (laughs)

[LOUIE] But it’s actually true. Sometimes they’re there. And sometimes they’re not. Which kind of gives me that sense of a magical land. These are actually in Lake Travis near Austin, or in the Austin area, and they’re a string of little islands or islets, dubbed the Sometimes Islands. They appear and they disappear based on how much rain, how full the lake is. So, when the islands are revealed, you usually know it’s a pretty bad drought in Texas, and when the water rises they disappear. So the peak of the island is about 665-670 feet, so the lake has to be below that level for them to show up. And it’s a really popular spot for kayakers. They love to paddle around and stop there. But it’s generally pretty rough and uninviting. Old-time locals say that the land was once used for cattle grazing before flooding took place. And sometimes when it’s been dry for a really long time, as it will do sometimes in Texas, they actually become a peninsula from the land and you can walk out and visit them from the Mansfield Dam park. But they’re just sort of an interesting name and an interesting concept. A little more romantic sounding than they are in reality.

[RANDALL] You know I’ve driven by, I believe it’s highway 620 around that area, and I have seen those islands during the...

[LOUIE] Right.

[RANDALL] …dryer months of the years. And you know it does make sense. Sometimes they’re there, sometimes they’re not.

[LOUIE] Right. It’s a cool phenomenon for sure.

[RANDALL] Well, you know I have to hand it to our listeners. Some of these Instagram comments were pretty darn funny. When we asked what the strangest formation in Texas was… (laughs), a lot of people just said “me.” I know Gumpisreal said Willie Nelson, said “Stoned, but not a geological oddity.” (laughs). 19rocky88 said “My wife sleeping.” (laughs) But I’ll tell you, the most mentioned formation of all, and I think it was kiarrai77, hobsratch, jeramyjacob, kevinadamsimagery, bigfoottx, teapotsrmything- that’s a cute name, pegmatite and pslynch82 and so many other people said E-Rock, and of course we know that stands for…

[LOUIE] Enchanted Rock. I think maybe the most famous place in Texas besides the Alamo. I really love the Instagram entry from kate.tx, who has the best description of Enchanted Rock. I’m going to use it for myself when I don’t have to be professional. She says: “Enchanted Rock- just a single granite batholith going ‘bwoop!’ up through much younger rocks.” (laughs) Isn’t that great?

[RANDALL] (laughs) That’s terrific, I love it.

[LOUIE] So what is it really in the less fun scientific terms, it was created a billion years ago when molten magma cooled and crystalized into granite under layers of rock far beneath the earth’s surface. So the hot liquid rock pushed up into the rock above in places and cooled and hardened very slowly turning into granite. And over time the surface rock and soil wore away. Those pushed up areas are the domes you see in the park that really are the iconic look that make you recognize it anywhere. Besides Enchanted Rock, there’s Little Dome, Turkey Peak and others. They are called exfoliation domes because they have layers like an onion. So those domes are a small but visible part of a huge underground area of granite and that’s what the batholith is, and the Enchanted Rock batholith stretches 62 square miles, most of it underground. They say climbing the rock is like climbing the stairs of a thrity or forty story building, and I’ve done it many times. It is just a wonder. If you want to live in Texas, you have got to climb Enchanted Rock, but don’t miss those other trails there, because they’re really a lot of fun too.

[RANDALL] Now does it get, let me ask you, does it get kind of hot up there in the summer?

[LOUIE] It does. It gets very hot up there in the summer.

[RANDALL] Yeah, so you probably want to wear some good shoes and take plenty of water.

[LOUIE] Right, you want to wear non-slip shoes, and if you’re going in the summer, try to climb early or late. Watch the sunrise or set up there. It’s really special.

[RANDALL] Well, finally Louie, one of our listeners on Instagram, innercityurbanadventurer, mentioned El Capitan because it’s made from coral.

[LOUIE] I thought that was so interesting. I think people often forget that this whole state used to be under the sea. So there actually was a Capitan reef now recognized as one of the most well-preserved fossil reefs of the world, and an exposed portion of that reef lifted up and was exposed by tectonic activity when the earth plates shift, and that is El Capitan. And if you are driving from Texas to New Mexico, you will probably see El Capitan for a portion of the journey as you’re crossing the border. And it is just the most magnificent sight. In fact, it was used as a landmark by travelers on the route later followed by the Butterfield Overland Mail Stagecoach Line. So it has been a landmark for ever since people have been in Texas.

[RANDALL] Wow, you know Texas has such a great geology doesn’t it? I mean.

[LOUIE] And we’ve barely scratched the surface. There are so many places, even on my little farm here I’ve found geodes, it’s just so amazing underneath this soil of Texas are some of the most amazing rock formations anywhere.

[RANDALL] You know, I think our listeners, if they do a little digging in their own backyard, they’re bound to find some surprising geology as well. Well Louie, thanks so much for joining me, from your farm, and I really appreciate your time. Thanks for educating us.

[LOUIE] You’re welcome Randall, and thanks for having me.


[SPONSOR] Support from Toyota allows us to bring you stories from Under the Texas Sky. Toyota has been a proud sponsor of the Texas Parks and Wildlife Foundation since 2002, providing generous support to help the department provide outdoor programs for Texans and to conserve the wildlife of the Lone Star State.

[NARRATION] Well we’re done wandering for this podcast…but Louie Bond and I—or our executive producer, Cecilia Nasti—will be back with more fascinating things to see and places to explore in the Lone Star State.

Before heading to any state park, historic site or natural area, call ahead.

Also, keep an eye on our Instagram account, which is @Underthetxsky. We’ll use it to notify you of some of the Wanderlist subjects we plan to cover, and give you a chance to ask questions, some of which we’ll answer on the podcast.

Under the Texas Sky is a production of Texas Parks and Wildlife. We produce our Wanderlist series in partnership with Texas Parks and Wildlife Magazine in the Media Production Studios in Austin, Texas. Yours truly did our sound design. Whitney Bishop does our social media. And we get distribution and web help from Susan Griswold and Benjamin Kailing.

Stream or download Under the Texas Sky and Under the Texas Sky’s Wanderlist wherever you get your podcasts. And please leave a review while you’re there and let us know how we’re doing and what you’d like to hear.

Until next time…keep on wandering Under the Texas Sky. I’m Randall Maxwell.