The Milk River country of northern Montana was one of the last regions of the northern plains to be incorporated into the American commercial economy, and the trading posts that appeared along its banks in the 1860s and 1870s were the first permanent structures that the Euro-American fur trade built in the region. Old Fort Belknap was among these posts, established in 1871 on the south bank of the Milk River, one mile southwest of the present town of Chinook, Montana. It was built by Nellie Peck and E.H. Durfee as a trading post for the North West Company, and it was named for William W. Belknap, who served as the United States Secretary of War at the time of its founding. The post operated for fifteen years before being discontinued in 1886, and the site it occupied is now a ghost town, a place where the physical evidence of the fur trade era has been largely erased by the passage of time and the transformation of the Milk River valley.

The decision to build a trading post at the Milk River location in 1871 was driven by the geography of the northern plains trade. The Milk River was a major tributary of the Missouri, and the country it drained was home to large populations of the Gros Ventre and Assiniboine peoples, who were among the most active participants in the fur trade of the northern plains. The trading post that Peck and Durfee built was intended to capture the trade of these communities, offering manufactured goods in exchange for the buffalo robes and beaver pelts that the Gros Ventre and Assiniboine hunters produced. The location on the south bank of the Milk River was chosen for its accessibility to the surrounding country and its proximity to the river crossing that the trade routes of the region used.

Nellie Peck was one of the more remarkable figures in the fur trade history of the northern Montana plains. A trader and entrepreneur who operated in the Milk River country during the 1870s and 1880s, Peck built a reputation for fair dealing with the Gros Ventre and Assiniboine peoples that distinguished her from many of the traders who operated in the region. Her partnership with E.H. Durfee in the establishment of Old Fort Belknap was part of a broader commercial network that extended across the northern plains, and the trading post she helped build was one of several commercial establishments that she operated in the Milk River country during her career.

The Gros Ventre people, who called themselves the Aaniiih, had occupied the Milk River country for generations before the arrival of the fur traders. Their territory extended from the Milk River south to the Missouri and from the Little Rocky Mountains west to the Sweetgrass Hills, a vast landscape that they knew intimately and that they defended against the encroachments of neighboring peoples. The arrival of the fur traders at Old Fort Belknap was not the first contact between the Aaniiih and the Euro-American commercial world; they had been trading with the Hudson's Bay Company and the American Fur Company for decades before Peck and Durfee built their post on the Milk River. But the establishment of a permanent trading post in the heart of their territory represented a new stage in the relationship between the Aaniiih and the commercial economy of the United States.

The Assiniboine people, who shared the Milk River country with the Gros Ventre, were also regular traders at Old Fort Belknap. The Assiniboine had a long history of engagement with the fur trade, having been among the first peoples of the northern plains to trade with the Hudson's Bay Company in the eighteenth century. Their participation in the trade at Old Fort Belknap was part of this longer history, and the goods they received in exchange for their furs and robes were integrated into the material culture of the Assiniboine community in ways that reflected both the utility of the manufactured goods and the cultural values that governed their use.

The decline of the buffalo herds in the late 1870s and early 1880s transformed the economics of the northern plains fur trade and made the trading posts that had depended on buffalo robe production increasingly unviable. The great herds that had sustained the Gros Ventre and Assiniboine economies for generations were gone by 1883, and the trade in buffalo robes that had been the foundation of Old Fort Belknap's commercial activity collapsed with them. The post continued to operate for a few years after the buffalo disappeared, trading in the smaller furs and hides that the remaining wildlife of the Milk River country produced, but the economic basis for its existence had been destroyed.

Old Fort Belknap was discontinued as a trading post in 1886. In the same year, the federal government was in the process of establishing the Fort Belknap Indian Reservation for the Gros Ventre and Assiniboine peoples, a reservation that would be formally established in 1888 and that would take its name from the trading post that Peck and Durfee had built on the Milk River. The Fort Belknap Indian Agency, which administered the reservation, was located thirty miles east of the original trading post, and the community that grew up around the agency adopted the Fort Belknap name. The original trading post site, one mile southwest of Chinook, became known as Old Fort Belknap to distinguish it from the agency and the reservation that bore the same name.

What Remains Today

The site of Old Fort Belknap is located on the south bank of the Milk River, one mile southwest of Chinook, the Blaine County seat. The physical evidence of the trading post's existence has been largely erased by the passage of time and the agricultural development of the Milk River valley, but the site retains historical significance as the location of one of the first permanent Euro-American structures in the Milk River country.

The Blaine County Museum in Chinook maintains records related to the history of the Milk River valley, including the fur trade era and the establishment of Old Fort Belknap. The museum's collections include materials related to the Gros Ventre and Assiniboine peoples and the history of the Fort Belknap Indian Reservation.

Visiting

Old Fort Belknap is located near Chinook, the Blaine County seat, on US Highway 2. Chinook provides visitor services and is accessible via US Highway 2. The Blaine County Museum in Chinook is the best starting point for visitors interested in the history of Old Fort Belknap and the Milk River fur trade.

The Fort Belknap Indian Reservation, located south of Harlem on US Highway 2, welcomes visitors and provides context for understanding the history of the Gros Ventre and Assiniboine peoples in the Milk River country. The reservation's visitor center and the St. Paul's Mission near Hays are significant historical sites in the region.