In the fourth interview session, conducted on February 8, 2001, McArthur shares his memories of the Columbia River before the construction of hydroelectric dams, and talks about how the Columbia River Gorge changed. He briefly discusses serving on the state advisory committee on historic preservation in the 1970s, and then talks about his recreational activities on Mount Hood, including climbing and camping on the mountain, and repairing the Snowshoe Cabin, the Cloud Cap Inn, and other buildings.