The Tshimakain Mission started in September 1838, with the arrival of Congregationalist missionaries Cushing and Myra Fairbanks Eells and Elkanah and Mary Richardson Walker to the area along Chamokane Creek at the community of Ford, Washington. Fort Colvile Chief Factor Archibald McDonald recommended the area to Eells and Walker on their first visit to the area. On April 23, 1838 after traveling to Independence, Missouri, the Eells, Walkers, William Henry and Mary Augusta Gray, Asa B. and Sarah Smith, and Andrew Rodgers, departed for the Oregon County with a Hudson Bay Company fur trader caravan to the Rendezvous. They arrived at Waiilatpu and the Whitman Mission on August 29, 1838.For the next nine years under the auspices of American Board of Commissioners for Foreign Missions, the Tshimakain missionaries lived with the Spokane people.
On September 16, 1838, Eells conducted the first Protestant service in Stevens County at Chewelah.In the fall of 1839, the missionaries started a school for the local Indians with 30 students rising to 80 over the winter.On January 11, 1840, Eells house burned. Local Indians responded quickly to assist. When the Fort Colvile leader Archibald McDonald heard about the fire, he dispatched four men to make the house habitable.In 1842, Elkanah Walker, with support from Cushing Eells, printed the Spokane Primer, a Salish language primer. This was the first book written in Washington.The winter of 1846-47 was the most severe in the memory of the oldest Indians. It triggered the loss of many domestic animals for Indians and missionaries.