The region between Las Vegas and California on Interstate 5 shows examples of several different ecosystems characteristic of the vast Mojave Desert and includes a portion of the Sierra Nevada range of mountains. The largest portion of Nevada is part of the Great Basin, but this region of Nevada is part of a different structure, the Mojave Desert and related areas. It was formed through a number of geologic forces over millions of years. The topography and climate have not been such as to attract large numbers of human inhabitants until the development of Las Vegas as an entertainment center, and the road from California has become a highly-traveled route precisely because of the creation of that metropolitan area. Those driving the route may see the environs as monotonous and repetitive, with vast stretches of desert territory that seem to be covered with the same type of vegetation and with the same rare sighting of animal life. The region is much more varied than a cursory examination would indicate, however, and also possesses more geologic structures than one might see without looking more closely.
The region under discussion was formed through various geologic forces that shaped much of California and Nevada. Geologic history in this area extends back about 1.8 billion years, but the visible part of the region's geology begins about 800 million years ago when the ancient continent of what is now North America broke in two, forming a new ocean basin. Sediments which alter would become sedimentary rocks were laid down along the new continental margin, and in some places, these rocks accumulated to thicknesses of several miles as the continental margin slowly sank. The Inyo Mountains and the area around Las Vegas consist of thick layers of sedimentary rocks dating from this era. This depositional coastline persisted through the Paleozoic period, during which Southern California was in shallow water and slowly took on a gr...