Who Claimed Colorado in 1706? (Nobody)

In 1706, no European power formally claimed Colorado. The region was inhabited by Ute, Apache, Comanche, and Arapaho peoples. Spanish claims dated to 1541 (Coronado expedition) but were notional; France claimed the Mississippi watershed (including eastern Colorado) in 1682 (La Salle). The U.S. acquired most of Colorado via the Louisiana Purchase (1803) from France; the southwestern corner came via the Mexican Cession (1848). Formal U.S. territorial organization began with Colorado Territory in 1861.