1700 The first French explorers reached the Rocky mountains.
1779 During the 1700’s various groups of Spanish and French explorers.
1806 Lieutenant Zebulon Pike leads a group of 15 soldiers in an attempt to scale Pike's Peak.
1819 Under the terms of the Adams-Onis treaty Eastern Colorado became American territory while the remainder was Spanish.
1835 Bents fort was completed near La Junta, it served as a rendezvous point for trappers and traders.
1842-53 John Fremont led five expeditions through Colorado while exploring the west.
1848 Under the terms of the treaty of Guadalup Hidalgo Colorado was ceded to the United States.
1858 Gold was found along the Cherry Creek where Denver is now located.
1870 Denver becomes linked to the national rail network.
1876 Colorado was admitted to the Union as the 38th state.
1880 was the peak of the silver boom which centered at Leadville whose population swells to 25,000 and whose town includes an opera house.
1915 The Rocky Mountain National was created.
1957 NORAD is established in Colorado Springs, the next year the Air Force academy is created there.