The Cascadians were organized in 1920 with 104 charter members. The founding president of the club was C. E. Rusk, a pioneer mountaineer in the Northwest, and the author of the book, Tales of a Western Mountaineer, published by The Mountaineers of Seattle. Throughout the years the purpose of the club has
been to promote interest in and enjoyment of non-motorized outdoor activities in the Northwest.

In its first decade, The Cascadians club was responsible for popularizing snowshoeing, tobogganing, and skiing inYakima, in addition to extending the limits of mountaineering experiences to anyone interested. The club was also responsible for having 90 acres set aside for the development of Boulder Cave and the camp and picnic grounds associated with it. With the  help of the Chamber of Commerce and the Forest Service, money was allocated to improve the grounds, build a lodge, and install a piped water system.

In the years since, The Cascadians has developed, or has been blessed with, some of the Northwest's most outstanding mountaineers. In earlier  years the Central Washington Mountain Rescue was maintained as a committee of The Cascadians. Although the Council now has its own autonomous organization, almost all of its members are also membersof The Cascadians. For many years, The Cascadians were instrumental in the development of ski areas locally and in the Cascades, and over its history has often assisted  in the construction or reconstruction of various trails in cooperation with the Forest Service.