The CVHS's mission is to maintain an association interested in the preservation of history for the lower Chehalis River Valley (eastern Grays Harbor).

In 1984, two young men, Randy Beerbower and Mike Clark, had a vision that the communities within the Chehalis Valley needed a museum to preserve the history of the area. As a result, the Chehalis Valley Historical Society was incorporated on August 27, 1984.

The first meeting of the organization was held on October 4, 1984, in Elma. The museum opened in the summer of 1985, in the old Rainier Bank Building in Elma Wa.

About two years later, the landlord tripled the rent, making it impossible to remain at that location. The museum later purchased the quaint, 1906 Scandinavian Lutheran Church at 703 W. Pioneer Avenue, Montesano, Wa., and reopened in its current location on March 19, 1988.