Site Stewards monitor historic cultural sites, and in doing so, they also observe Nevada’s striking geology. That geology has influenced how people moved across and settled the landscape, making it an essential part of understanding any cultural place. Our State is full of incredible geologic features. Ones that shine bright as the new day dawns or sparkle as the sun sets each night. Some are craggy, round, and even flat. Granite, Sandstone, Limestone, and remnants of ancient volcanoes and underwater life. And the land is rich with fossil remnants of all sizes. From the official state fossil, a giant marine reptile named Ichthyosaur from the Triassic period around 250 million years ago, down to the smallest Precambrian algae, Elainabella deepspringensis, which is 560 million years old. This tiny algae was a new species discovery in Esmerelda County in 2014 by UNLV Paleontologist, Steve Rowland and his crew.
But how did these geological wonders get to be in our backyard? First, Nevada was a part of a massive sea and when those seas subsided it left behind not only the marine fossils but beaches, which later hardened and now provide us with Sandstone mountains. As the tectonic plates changed their dance moves, the Basin and Range Province was formed. This is a process where the Earth’s crust stretches sideways and thins, causing cracks. These cracks then allow for the pushing up of high mountain ranges and flat valleys. This process is continuing today and has given Nevada some amazing landscapes.
To see great examples of these processes, take a relaxing day trip on Highway 93 on the Eastern side of our state. A great guidebook for this trip is “A Geologic and Natural History Tour through Nevada and Arizona along U.S. Highway 93” published by Nevada Bureau of Mines and Geology, University of Nevada Reno. The guide includes GPS Coordinates and gives information on early travelers of this path, the three deserts, geology, and plant life which can all be viewed from the highway. The road starts in Wickenburg, AZ. And ends at the Nevada-Idaho stateline outside Jackpot.
Although Highway 93 begins at the stateline with Arizona at Hoover Dam, my husband and I used this guidebook for a trip from Las Vegas to Pioche. We left out early on a Sunday, coffees in hand, and a plan to learn about the formations we always remarked on every time we traveled this route. We opened this book where Highway 93 jockeys off from Interstate 15 at Apex, where the highway signs reminds you this route is designated as the Great Basin Highway. At mile marker 53 and 54 we learned about the Arrow Canyon Range and limestone outcrops visible on the left side of the highway. We continued to mile marker 76.6 wherwe read about the notch on the skyline known as Alamo breccia. This notch consists of “material swept into place and deposited by tsunamis resulting from a meteorite that plunged into the sea” that once covered this part of the state. By mile marker 23.6 in Lincoln County, we could see dark rock on the right of the highway. This is a “basalt flow that overlies welded ash-flows tuffs”. Most of us know this area when passing Lake Maynard (dry most years-I have only ever seen water in it one time) on the right before dropping into lower Pahranagat Lake.
Alamo Breccia location (Wilson44691, Public domain, via Wikimedia Commons)
Further up the highway, you can pull over and hunt for Trilobites. Yes, real fossil hunting in Nevada. Mile marker 81.3, still in Lincoln County, you will see a sign for Oak Springs Trilobite Site where you can collect Trilobite fossils. But beware, you are on your own to find the rocks that contain these fossils. We gave it about an hour of searching and were skunked! But if you have more time, you could get lucky and find one.
Mile Marker 108 is the entrance to Cathedral Gorge State Park. The State Park are remnants of sediment left behind when “Meadow Valley and Lake Valley were occupied by a fresh water lake”, later dried up. The sediments include volcanic ash that later became soft silt and clay. Due to erosion, this left behind narrows and spires and labyrinths. If you have never been, it’s worth the visit. If you don’t have time for hiking or seeing the Visitor Center, stop at Miller Point at mile marker 110.9 for an easy walk out to get a bird’s eye view of the Gorge.
Nevada is full of mining history and an easy place to see this from highway 93 is mile marker 109.1, where a historical marker for Bullionville stands. This town once processed the ore from the mines of Pioche. The dark piles on the right side of the road are remnants from the smelter that processed the tailings from 1890.
Bullionville Historic Marker
Reaching the outskirts of Pioche, at mile marker 116.2 the road diverts to State Route 321 to downtown Pioche. Pioche is a must-see if you love old Nevada towns and mining history. Don’t forget to get yourself some ice cream at Gunslingers on Main.
Pioche, Nevada
This guidebook offers so much more interesting information than I can add here. With photographs, easily comprehended explanations of the differing geology, common flora and fauna, cool historical tidbits and side trips, it’s a must have. If your geology-based vocabulary isn’t as good as you would like, they did a great job with a Glossary at the end, as well.
We thoroughly enjoyed our day trip on Highway 93 and learned a lot about the fantastic views we had always marveled at. Upthrusts, Caldera, Russian Olive, and Mistletoe are all new topics for us to explore as we continue to enjoy the state we call home.
