December 1956 (age 57)

Nothing to report.

December 1971 (age 72)

In early December, Sigurd had lunch at the National Geographic Society office in Washington, D.C. to work out the details of an agreement for him to write the introduction to a book on wilderness that the society was planning. He would work on it over the winter, and finish it in the summer of 1972. The book, Wilderness U.S.A., came out in 1973. Sigurd's introduction is titled "A Longing for Wilderness."

Meanwhile, National Park Service Director George Hartzog wrote on Dec. 27 to thank Sigurd for his work on the Yellowstone National Park Master Plan, and added, "You are a marvelous, warm, wonderful human being, and it is a great delight to work with you." Finally, in December the Sierra Club's Board of Directors made Sigurd an honorary life member of the club.