The nationally significant Bent's New Fort in the Lamar vicinity was built by William Bent in the winter of 1852–1853. The fort was used as a trading post and the Upper Arkansas Indian Agency from 1853 to 1859, after which time the U.S. Army leased it from 1860 to 1866.
A key contemporary figure, Bent was married to Owl Woman, and allied with her father, White Buffalo, Cheyenne Keeper of the Arrows. Bent’s New Fort is significant under transportation, commerce, military, social history, and exploration/settlement, and is associated with the Historic Resources of the Santa Fe Trail Multiple Property Documentation Form. On November 28, 1864, Colonel John M. Chivington led his soldiers to the murderous Sand Creek Massacre of a peaceful Cheyenne and Arapaho encampment from the fort. For more information, see: