Wyoming is a state with two landscapes. There are pine-covered mountains where patches of snow never melt, and there are miles of sagebrush and cactus where even big creeks go dry. Luckily for me, I get to see both, since the last part of the trip takes us south to cowboy country in the Seminoe Mountains.
To get there, we need to drive from Buffalo, WY (population 3,900) to Casper, WY (population 53,569). Along the way, we make two important stops for Taylor’s research—first sampling a site and second measuring the uplift of the younger Bighorn rocks.
The site we stop for is part of a huge dike that potentially runs all the way to our destination. Since the rock cools more slowly towards the center of a dike (away from the colder rock into which the magma intrudes) the rock has a coarser grain in the middle than at the edges. In the case of really wide dikes like this one, the magma separates so that it forms a different kind of rock in the middle of a site.
Here, the rock is also similar to what Taylor looked at last summer in the Wind River Mountains, and he wants to test the site to see if dikes like this one actually run underground all the way across the state. By comparing this rock with the rock from sites down south, he hopes to demonstrate that these intrusions were part of the same geological event. Since earlier research shows that some of these southern sites are within the right date range for Taylor, similar northern sites are good contenders for determining the position of the Wyoming Craton 2.6-1.7 billion years ago.
At our second stop, Taylor takes the strike (the horizontal measurement) and the dip (the downward angle the rock relative to horizontal) of younger sedimentary rocks in Crazy Woman Canyon. Taylor needs these measurements so he can correct his data to tell what the landscape looked like in the time period he’s studying—before pieces of the Wyoming craton were pushed upwards 70 million years ago by later geological activity.
After working in the morning, we stop at a gas station in Kaycee, WY (population 249) where we acquire a big bag of beef jerky. I’ve never tried it before, but despite my initial suspicion (the brand, Tillamook, is also a brand of chewing tobacco), it’s pretty good.
The landscape outside the window is changing fast, and we drive for 30 miles without seeing any sign of human habitation on the road. On the outskirts of Casper, Wyoming’s second largest city, I see farm equipment for sale, and crumbling pre-fab houses sending bits of tar paper into the wind.
Downtown Casper is equally empty, although large bronze statues of famous cowboys decorate the street corners. Though we’ll be back tomorrow, our target tonight is the Bureau of Land Management (BLM) land around Casper.
Reading the rules of conduct on BLM land, we learn that though camping is allowed, homesteading is not. I start to flash back to my AP US history textbook. Homesteading? Squatting on public land for so long the government can’t remove you? I’m surprised they still have to mention that this is no longer a possibility. Then I notice that homesteading has only been illegal in Wyoming since 1976.
As we pull over to check the maps for a good campsite, the county sheriff pulls up in his truck to check on us. Maybe he thinks that since we’re out here in the desert, we must be peyote-drugged vision questers. When he learns that we’re geologists, he decides to move along.
The sun sinks as we set up camp, and a warm breeze fills the air. After dinner, we watch the sky, trying to learn the constellations with Taylor’s Iphone. After a while, I give up and just stare, smelling the sharp scent of wild sage as shooting stars pass overhead.
The next day we set out and sample five sites, though bushwhacking through this country is not as easy as it was in the Bighorns. Cacti are everywhere, and we all have spines in our boots and fingers by the end of the day. Taylor jokes that the last people to come here must have been the geologists who made the map we’re using. I actually think he may be right—we don’t see any other people or cars all day.
As we drive back into Casper, herds of pronghorn antelope run across the road. Though it’s been a long time since I heard the song “Home on the Range,” I can’t seem to get it out of my head.