 The canyon held an intact ancient forest of Douglas Fir, Western Hemlock and Western Redcedar, estimated to be millable into up to 340 million usable board feet of timber.With the creation of the Skagit River Hydroelectric Project in the 1910s, the first two dams, Gorge Dam and Diablo Dam, were constructed downstream of the Ross Dam site.In 1937, construction began on the dam, originally slated to be called "Ruby Dam", on the first two of four planned construction phases.