Tom Gill was born in Philadelphia, Pennsylvania. In 1913 he graduated from the University of Pennsylvania with a major in languages. In 1915, he earned his Master of Forestry degree from Yale University. He went to work for the U.S. Forest Service as a forest ranger in Fort Collins, Colorado. During World War I, he was a pilot and instructor in the Army Air Service. After the war he returned to the Forest Service as forest supervisor of the Black Hills National Forest at Deadwood, South Dakota. In 1922, he was transferred to Washington, D.C. where for the next three years he was in charge of information for the Branch of Public Relations, in charge of educational activities, editing and writing magazine articles, writing and directing motion pictures, and preparing speeches and articles for the chief forester. In January of 1925, he became associate editor of the American Forestry Association's magazine, American Forests and Forest Life. In 1926 he became executive director of the Charles Lathrop Pack Forestry Foundation in Washington, D.C., where he stayed until the Foundation's liquidation in 1960. Although he was a quiet man, he was a prolific writer. Much of his work was fiction, 12 novels of adventure involving cowboys, forest rangers, and frontier characters. His first book was published in 1930, and the last was published in 1946. But he was much more interested in forestry than he was in fiction-writing, and he also wrote books about forestry. He co-authored Forests and Mankind with Charles Lathrop Pack, which was published in 1930. He also wrote Forest Facts for Schools, which was the most widely-distributed school book on forestry in its day. His Tropical Forests of the Caribbean (1931) was the definitive work on the area. With Ellen Dowling he compiled a book for the American Tree Association called the Forestry Directory (1943). He also wrote Land Hunger in Mexico (1951).