April 1950 (age 51)

In one of his first actions on behalf of wild places outside of the Quetico-Superior wilderness of Minnesota and Ontario, Sigurd testified in Washington on April 3 against a proposed water power project in the West that would inundate Dinosaur National Monument (today it is a national park). It would become the biggest conservation battle of the decade, and their eventual victory would give conservationists the momentum to introduce a bill to create a national wilderness preservation system.

April 1965 (age 66)

Sigurd began the month in San Francisco at the 9th Biennial Wilderness Conference, sponsored by the Sierra Club. He told attendees that spiritual values are "the real reason for all the practical things we must do to save wilderness," and he ended his talk (which was called "The Spiritual Need") as follows: "Unless we can preserve places where the endless spiritual needs of man can be fulfilled and nourished, we will destroy our culture and ourselves."

After the conference he spent a couple of weeks in Washington in his role as a consultant to the Park Service, and as vice-president of the Wilderness Society testified in favor of bills to establish the St. Croix National Scenic Waterway and a wild rivers system. He spent the end of the month in Ontario, first in Toronto, where he met with the National and Provincial Parks Assocation and attended a Quetico-Superior Foundation banquet, then in Ottawa, where he encouraged Canadians to protect portions of the Yukon adjoining Alaska's Arctic Wildlife Refuge.