Robert W. Mezger was born on December 8, 1922 in Jersey City, New Jersey. After graduating from high school, he began studying at Penn State University. He took a break from his studies to join the U.S. Army Air Corps, where he served as a second lieutenant from 1942 to 1945. While serving in Denver, Colorado, Mezger met Patricia Cosley at a USO dance. They were married in 1945. Robert Mezger returned to Penn State and graduated from forestry school in 1947. Later he received his master's degree from the University of California at Berkeley. After becoming a forester for the Bureau of Indian Affairs, Robert Mezger took a position with the Klamath Indian Reservation in 1952. In 1959 he accepted a job at the U.S. National Bank Trust Department, where he worked until his retirement at age 65. Robert Mezger remained in the Klamath Basin and began purchasing forest property. In 2008 Mezger was named the American Tree Farm's Western Region Tree Farmer of the Year. In 2013 he published a book A Forest History of the Oregon's Klamath Basin 1910-1980. He continued to work in the industry until his death on January 9, 2014.
Collection contains documentation on the accounting and timber sales at the Klamath Indian Reservation, such as: documentation of the Klamath Indian Management Trust, timber sale ledgers, timber growth and forest inventories, trust agreements, Appraisal of the Property of the Klamath Tribe of Indians, the Klamath Tribe sales program, talk by Robert Mezger, proposed marking regulations for the Klamath Indian Reservation by Patrie, book by Robert Mezger "A Forest History of Klamath County" and other materials