During the 1850’s and 1860’s, the population growth of the Colorado Territory increased due to the discovery of gold and silver in the Rocky Mountains. The Colorado Territorial Governor, John Evans, wanted the Cheyenne and Arapaho hunting grounds available for white development. The Indians refused to sell their lands and move to the reservations for settlement. The angered Indians attacked wagon trains, stagecoach lines, and mining camps. The governor requested that Colonel John Chivington and his volunteer militiamen go out and talk to the Indians about giving up their lands. At Camp Weld, near Denver, the Indian representatives met with Evans and Chivington on September 28, 1864.
No treaties were signed and the Cheyenne and Arapaho, thinking they would have protection of the soldiers of Fort Lyon, traveled to Sand Creek to set-up their village. Chivington knew that the Indians had surrendered. On November 29, 1864, under Chivington's command, seven hundred men from the Colorado Territory Militia attacked and destroyed an encampment of Cheyenne and Arapaho Indians at Sand Creek in southeastern Colorado Territory.
Over one hundred Indians were killed: most of them were old men, women, and children, including Cheyenne Chief Yellow Wolf as well as his brother. Chivington resigned from military service but he was never convicted for the Sand Creek killings.