Boss Plains By winterhwt Oct 1, 1848 United States Takes Over Western Colorado Period: Oct 1, 1848 to Oct 30, 1876 Colorado Timeline Jul 1, 1859 Gold Is discovered Oct 1, 1859 Thousands of Prospectors and Settlers Enter Colorado Feb 1, 1861 The Colorado Territory Is Established Aug 1, 1870 Railroads Reach Denver Aug 2, 1876 Colorado Becomes the 38th State
