First visited by Spanish explorers in the 1500s, the territory was claimed for Spain by Juan deUlibarri in 1706. The U.S. obtained eastern Colorado as part of the Louisiana Purchase in 1803, the central portion in 1845 with the admission of Texas as a state, and the western part in 1848 as a result of the Mexican War.
East of the Front Range of the Rocky Mountains are the Colorado Eastern Plains, the section of the Great Plains within Colorado at elevations ranging from 3500 to 7000 ft (1,000 to 2,000 m). Kansas and Nebraska border Colorado to the east. The plains are sparsely settled with most settlements along the South Platte and the Arkansas rivers and the I-70 corridor.
The state's economy broadened when irrigated agriculture developed, and by the late 19th century livestock raising had become important. Early industry was based on the processing of minerals and agricultural products. Current agricultural products are cattle, wheat, dairy products, corn, and hay.
Breathtaking scenery and world-class skiing make Colorado a prime tourist destination. The main tourist attractions in the state include Rocky Mountain National Park, Curecanti National Recreation Area, Mesa Verde National Park, the Great Sand Dunes and Dinosaur National Monuments, Colorado National Monument, and the Black Canyon of the Gunnison National Monument