Originally built for John Jacob Astor’s Pacific Fur Company, it was the first American-owned settlement within Washington state, located in what is now Okanogan County.

PFC employees progressed up the Columbia River in 1811 accompanied by a NWC party led by David Thompson as far as the rapids at Celilo Falls.

As PFC continued up the Columbia, trade goods of the NWC were found among inhabitants near Fort Okanogan's eventual location.

The Okanagan dignitaries agreed to maintain friendly relations with PFC employees, partake in the beaver trappings, provide security for the station and ensure its workers were always fed.

Nights were a constant source of worry for the lonely Ross, despite having several hundred "friendly inclined" natives encamped nearby performing sentry duties.

Besides the new housing for the fort staff "a spacious store for the furs and merchandise, to which was attached a shop for trading with the natives" were completed as well.

Cox and a small party of French-Canadians and Hawaiians along with several Okanagans led by a local headman, Red Fox, set off to locate the equines.

Cox took back the company horses without bloodshed, in part from consideration of potential Sanpoil attacks on the seasonal fur brigades departing from Spokane house.

Negotiations for the sale of its property within the United States were still ongoing with the American Government, with the HBC unwilling to lose its basis for land claims of Fort Okanogan.

Duchoquette left with a pack train on 18 or 19 June, leaving the post "for all practical purposes abandoned..." and later established a trading outpost outside Keremeos in British Columbia.

[4] Robert Stevenson, a witness to the withdrawal recalled that:At the time of our visit all the Indians in that part of the country were congregated at the fort assisting the factor in packing up the goods preparatory to moving the post to Keremeos in British Columbia.