September 1952 (age 53)

Nothing to report.

September 1967 (age 68)

Sigurd spent a few days early in the month at Sequoia National Park in his role as an advisor to the Park Service. He and Starker Leopold and Charles Olmsted made up the Park Service's Advisory Committee on Research. They recommended that the Park Service hire three new research biologists, and endorsed the recommendation of Sequoia King's Canyon staff to start some prescribed burning in the King's River high country where the danger of fire escaping was at a minimum. The idea of prescribed burning was still very young, relatively untested, and publicly controversial after decades of Smokey Bear campaigns by the U.S. Forest Service. Olson's committee wanted one of the new biologists to be put to work studying the prescribed burn's effects.

Sigurd spent the middle part of the month at home speaking and lobbying on behalf of the creation of Voyageurs National Park, and the final two weeks he spent out east doing work for the Park Service and attending the Wilderness Society annual meeting.