Bent's Old Fort is an 1833 fort located in Otero County in southeastern Colorado, USA. William and Charles Bent built the fort to trade with Southern Cheyenne and ArapahoPlains Indians and trappers for buffalo robes. For much of its 16-year history, the fort was the only major white American permanent settlement on the Santa Fe Trail between Missouri and the Mexican settlements. It was destroyed under mysterious circumstances in 1849.