Henry Byron Mock was born on February 1, 1911, in Greenville, Texas, to Henry Byron Mock and Ellena Edmonds Mock. He graduated from Tuscon High School in 1929 and graduated from the University of Arizona in 1933. Because of the Great Depression, Mock was unable to attend graduate school immediately after graduating, so he moved to Hollywood, California, and accepted a job as the secretary of the general manager of Fox Film Studios. After about a year, Mock left Hollywood and enrolled in Georgetown Law School. He graduated in 1939. The following year he received a position at the Department of the Interior, Solicitor's Office, and subsequently was appointed Chief Counsel of the U.S. Grazing Service, and moved to Salt Lake City, Utah. In 1942, Mock was drafted into the U.S. Army at Fort Douglas, and the next year he entered Judge Advocate General (J.A.G.) school at Ann Arbor, Michigan. He spent the next few years stationed in the Mediterranead Theatre of Operations, mostly in Naples, Italy. After the war, Mock was appointed the Regional Director for the Colorado and Utah region of the Bureau of Land Management (BLM), until he resigned in 1955, and started his own private legal practice in Salt Lake City. For many years, Mock was the attorney for the Utah-based Preston Nutter Corporation (a cattle and ranching business) in cases involving land, water, and grazing rights. He also dealt with mining issues in the West, and was involved with the Public Land Law Review Commission (PLLRC). He died on September 6, 2006, in Salt Lake City, Utah.