The first few years at Fort Nisqually were occupied with fur trading, the cultivation of some crops and a successful stock raising operation.

In 1840 The Puget Sound Agricultural Company was formed to supply farm produce, dairy products and meat, both locally and to such far away places as Hawaii and Russian Alaska. Settlers, new to the area, as well as visiting ships were re-stocked with food stuffs provided by the agricultural concern. The Puget Sound Agricultural Company (PSAC) was too large an operation to be run as part of the Hudson Bay Company (HBC). PSAC would concentrate on agriculture and the HBC would run the fur trade. It became a subsidiary (companion company) of the Hudson Bay Company with its headquarters located at Fort Nisqually.

A second or less obvious reason for The Hudson Bay Company to expand into farming operations was to strengthen its claims to greater expanses of land.

Its largest farm was the Cowlitz Farm located near the Cowlitz Portage. Maps record it as near the mouth of the Cowlitz River on a plain. Begun in 1838 with 95 head of cattle, the farm soon expanded with the building of barns under its first manager Chief Trader Tod. Soon the farm had 550 acres tilled for crops.

Other Farms that made up the Puget Sound Agricultural Company were the, Kull Kullee Farm, Muck Farm, Puyallup Farm, Sastuc Farm, Spaheuh Farm, Steilacoom Farm, Tenalquot Farm, Whyatchie Farm, and Yelm Farm.

The Company brought sheep from Mexico and both sheep and longhorn Spanish cattle from its posts in California. In the areas surrounding Fort Nisqually, about 13,000 sheep and 8,000 cattle and 300 head of horses grazed on the prairies.

The Hudson Bay Company claimed ownership of all land between the Nisqually and Puyallup Rivers and sixty miles south and east to Mount Rainier.