By Bob Harner
After the Mexican-American War, converging events made finding a southern route to the West increasingly more urgent. The 1849 California Gold Rush launched a flood of westbound travelers, most following existing northern trails from St. Louis. Winter snows made these trails dangerous or impassable. Adding to the pressure was the Army’s need to supply new western posts created following the Treaty of Guadalupe Hidalgo. The Army Corps of Topographical Engineers was tasked with answering these needs.