The Southern Snake Range décollement is the main geological feature in Great Basin National Park. It is a low-angle fault that is part of a collection of twenty-five metamorphic core complexes that stretch from Canada to northwestern Mexico. The park also contains three granite volcanoes that were formed during the subduction of the Pacific Plate beneath the North American Plate in the Mesozoic era.
Great Basin National Park is home to a diverse landscape including igneous intrusions, glacial features, and desert topography. The park is located in the northern part of the Basin and Range physiographic province and boasts the second tallest mountain in Nevada, Wheeler Peak, which stands at 3,982 meters. It was also once the home of the world's oldest known tree, a bristlecone pine.
At the southern end of the park lies Lexington Canyon, where you can find the only limestone arch in the southwest. Lexington Arch stands at an impressive 23 meters and is carved in the Notch Peak Limestone.
Great Basin National Park showcases a variety of landforms associated with arid regions, including alluvial fans, bajadas, bolsons, playas, and pediments. These can be seen from the park's overlooks and peaks, providing stunning views of the unique terrain.
Great Basin National Park is home to Lehman Caves, a limestone cave system considered one of the most stunning and diverse in North America. The caves were discovered by Absalom Lehman in 1885 and contain intricate marble formations, stalactites, stalagmites, flowstone, popcorn, helictites and other cave features. These features are formed as water runs through the cave, dissolving carbonate rock and depositing it in other areas of the cave.
The caves are divided into two levels, the upper and lower. The upper level has a large number of formations including stalactites, stalagmites and helictites. Stalactites form when calcium carbonate drips from the ceiling of the cave over time, while stalagmites grow from the floor. Helictites look like thin, fragile strands of straw and are formed by water flowing in an unpredictable pattern due to surface tension.
The lower level has a variety of large rooms, some with impressive formations such as the Parlor Room where visitors can see a number of crystals up close. Other features on the lower level include flowstone cascades, draperies, columns, and popcorn clusters.
The caves are a living environment and are home to several species of blind cavefish, bats, salamanders and beetles. Visitors should remember that the Lehman Caves are fragile and must be protected. Any food or drinks should be kept out of the cave as well as any artificial light sources like flashlights or lighters.