The Indigenous peoples of the Great Basin are Native Americans of the northern Great Basin, Snake River Plain, and upper Colorado River basin. The "Great Basin" is a cultural classification of indigenous peoples of the Americas and a cultural region located between the Rocky Mountains and the Sierra Nevada, in what is now Nevada, and parts of Oregon, California, Idaho, Wyoming, and Utah. The Great Basin region at the time of European contact was ~400,000 sq mi (1,000,000 km2). There is very little precipitation in the Great Basin area which affects the lifestyles and cultures of the inhabitants.