In 1914 he moved again to California. He served in the Navy there and in Washington, D.C., during World War I. In 1922 he set up his own accounting firm in San Francisco. In 1936 he brought in Clifford Heimbuchder, who soon became a full partner in the firm, renamed Farquhar and Heimbucher. Farquhar was active in the
Sierra Club, serving on its board of directors from 1924 to 1951 and president in 1933-1935 and 1948–1949. He served as
Sierra Club Bulletin editor from 1926 to 1946. Farquhar was a mountaineer who invited
Robert L. M. Underhill to introduce proper use of modern Alpine rope techniques to Sierra Club members on an annual club
High Trip in 1931. He made multiple
first ascents. On August 26, 1921, he completed the first ascent of
Middle Palisade by the south-west chute with
Ansel Hall. He was the author of numerous articles for the Sierra Club and the
California Historical Society, some of which were reprinted in book form. In 1956-59 he was editor of the
American Alpine Journal published by the
American Alpine Club. He edited and wrote forewords for several books on California history. His best known book is
History of the Sierra Nevada (1965), which is still in print. In addition to serving as Sierra Club president, he was president of the California Society of Certified Public Accountants (1942–43),
California Academy of Sciences (1950-53), and the California Historical Society (1960–62). In 1965 he was awarded the Sierra Club's
John Muir Award for distinguished work as a conservationist and mountaineer. He received the Henry R. Wagner Memorial Award of the California Historical Society in 1966. The
University of California at Los Angeles conferred on him the honorary degree of Doctor of Humane Letters in 1967. ==Family life==