In the early 1800s, the upper Missouri River Valley was a virtually untapped resource for fur traders. As long as the Mississippi River provided enough bounty for all, there was little motivation to tread deeper into Indian country. But as the pelts became harder to find, traders looked farther West for new resources.

Early fur trading, east of the plains, included very few buffalo hides. Introduced to the market as traders moved west, demand for the hides increased exponentially over the next few years. Safe passage through the area required the cooperation of the native tribes that inhabited the region—the Arikara, the Mandans, and the Sioux. When the fur trade was focused on the smaller pelts of the mink, otter, and beaver, the native tribes were not particularly interested in trapping. But as demand for buffalo hides increased, the native people, particularly the Teton Sioux, joined the hunt and were active participants in the procurement of buffalo hides.

The success of the fur trade was intimately tied to relationships with the native tribes and to peaceful relationships between tribes. There were several skirmishes, however, between tribes and between the tribes and traders, including a joint white and Teton Sioux war with the Arikaras in the 1820s. In 1825, the Atkinson-O’Fallon Commission traveled up the Missouri charged with the task of negotiating treaties with the upper Missouri tribes. It was a successful expedition. The fur trade initially brought wealth to the tribes in the form of cooking utensils, guns, blankets, and other material goods, but also eliminated the economic stability of the tribes and introduced whiskey to a population vulnerable to its abuse. By the 1850s, the heyday of the fur trade was over.