An area between the Sierra Nevada and Wasatch mountain ranges that no rivers flow out of. Covering most of Nevada, and parts of California, Oregon, Idaho, and Utah, the Great Basin is mostly a high desert area.
In prehistoric times, much of the Great Basin was covered by Lake Lahontan (in what is now western Nevada) and Lake Bonneville (Utah). Modern day remnants of these former inland seas can be found in the lines marking the water levels along the mountain sides, the fossils of sea creatures, and the smaller remaining lakes such as the Great Salt Lake and Pyramid Lake.
Parts of the Great Basin have been set aside in the Great Basin National Park in eastern Nevada, the Black Rock Desert-High Rock Canyon Emigrant Trails National Conservation Area in western Nevada, and various other national forests and designated wilderness areas.