On 29 April 1998, The Mountaineers donated most of the artifacts held by the club at that time to the Washington State Historical Society (WSHS). The deed of gift described the donation as a "collection of climbing gear, clothing, skiis, and materials related to climbing." The written agreement, signed by Mountaineers Executive Director Steve Costie and WSHS Head of Collections Lynn Anderson, declared the gift to be "outright and unconditional." Lynn Anderson wrote a short article about the donation for the WSHS History Highlights quarterly newsletter. The full, unedited version of her article is here.

The summary below was returned by WSHS to The Mountaineers shortly after receipt of this gift. It includes a brief description of each object in the collection along with both the WSHS and Mountaineer catalog ID's. (Notes in the right column were later added by the Mountaineers History Committee.) WSHS subsequently spent three months creating a detailed catalog of the collection. The WSHS catalog notebook was said to be about six inches thick.