From about 1837 until 1850, more than a quarter million buffalo robes bought from Indians and 27 tons of fur company trade goods were hauled over the 300 mile long Fort Pierre-Fort Laramie Trail, which followed the White River through this area. First used by the American Fur Company, the trail originated as part of an earlier Spanish trade route from Santa Fe to the Missouri River in present South Dakota. During the 1840s, it was the shortest overland connection between trading posts on the Platte and steamboats plying the Missouri. After the government purchased Fort Laramie in 1849, Colonel Aeneas Mackay and Captain Stewart Van Vliet traveled the trail to Fort Pierre with ten mounted riflemen, and General William S. Harney's troops marched over the route in 1855, when Lieutenant G. K. Warren of his staff mapped it. Small traders and government freighters continued to use portions of the trail until the 1880s, and ruts from the passage of thousands of carts and wagons can still be seen in several places between Fort Laramie and Fort Robinson.