Andrew Whitley Sublette, brother to William, Milton, and Solomon, helped establish a trading post with Louis Vasquez in 1835. The present day, Fort Vasquez, located on Highway 85, next to Platteville, Colorado, is a reconstruction. After selling the trading post in 1840, Andrew left the mountains and was seen in El Pueblo around 1844 and 1845 (present day Pueblo, Colorado), traveling along the Arkansas River, following herds of American Bison.
He was killed in an encounter with a grizzly bear in Southern California in 1854. Sources variously place the site of his death as Santa Monica Canyon or nearby Malibu Canyon.
- Lecompte, Janet; Pueblo, Hardscrabble, Greenhorn: Society on the High Plains, 1832—1856; University of Oklahoma Press; Norman; 1978; ISBN 0-8061-1723-0
- Noel, Thomas J. and Faulkner, Debra B; Colorado: An Illustrated History of the Highest State; American Historical Press; Sun Valley, California; 2006; ISBN 978-1-892724-52-6; ISBN 1-892724-52-9
- Brotemarkle, Diane; Old Fort St. Vrain: Diane Brotemarkle; 2001; Johnson Printing; Boulder, Colorado; ISBN 0-9712372-0-4