Mission was the site of what today is called St. Mary’s Mission. Established as Omak, November 26, 1902. Etienne de Rogue renamed it to Mission on April 3, 1907.

Father Etienne de Rogue a French Jesuit had charge of the St. Mary’s Mission which he founded in 1889. Chief Joseph and Chief Moses attended services here and the priest fluently spoke the Salish tongue in his work with the Indians. The name of the mission was St. Mary’s from the start, but the priest chose Omak in naming the post office, perhaps because the Indians referred to it as such. When the present Omak settlement sought a post office, Father de Rogue was persuaded to change the name to Mission. The mission has suffered a series of fires over the years but has continued to operate.