Fort Vasquez Trading Post, constructed in 1835, was the first permanent structure built along the South Platte River. Louis Vasquez and Andrew Sublette of St. Louis established their adobe outpost on a low plateau near the Trappers’ Trail. They wanted to be near the Cheyenne and Arapaho Indians, who traded buffalo robes for blankets, beads, kettles, knives, guns, ammunition, and other manufactured goods. Each year the traders traveled to St. Louis with their furs and returned with wagonloads of trade goods drawn by mule teams along the Santa Fe Trail and then north to the fort. Vasquez and Sublette employed as many as twenty-two men each year to serve as traders or hunters for the fort. The founders abandoned the fort in 1842 and its walls eroded into the soil.
A century later, the Platteville community spearheaded an effort to reconstruct the adobe outpost with assistance from Weld County and the federal Works Progress Administration. The project provided temporary employment for 59 local men during 1935 and 1936. In 1958, title to the property was transferred to History Colorado (then the Colorado Historical Society). With a major restoration and enhancement project in 2005 came an upgrade to the existing adobe walls, new interpretive panels, and a life-sized bison sculpture.