The first inhabitants of Colorado were American Indians. They were Arapaho, Cheyenne, Comanche, Kiowa, Pawnee, and Utes. Spanish explorers came to Colorado in the 1600's. In 1803, the United States bought eastern and central Colorado as part of the Louisiana Purchase. In 1858 prospectors found gold along Cherry Creek, near what is now Denver. That brought many new prospectors to the area. On August 1, 1876 Colorado became a state. In 1858, several parties of gold seekers bound for the California Gold Rush panned small amounts of gold from various streams in the South Platte River Valley at the foot of the Rocky Mountains in then western Kansas Territory, now northeast Colorado. The gold nuggets initially failed to impress the gold seekers, but rumors of gold in the Rocky Mountains persisted, and several small parties explored the region. In the summer of 1857, a party of Spanish-speaking gold seekers from the New Mexico Territory worked a placer deposit along the South Platte River about 5 miles (8 km) above Cherry Creek (in what is today the Overland Park neighborhood of Denver. Ralston continued on to California, but returned to 'Ralston's Creek' with the Green Russell party eight years later. Members of this party founded Auraria (later absorbed into Denver City) in 1858 and touched off the gold rush to the Rockies. The confluence of Clear Creek and Ralston Creek, the site of Colorado's first gold discovery is now in Arvada, Colorado.

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