Harold Verne Keith, the son of Malcolm Arrowwood and Arlyn Kee Keith, was born on April 8, 1903, in Lambert, Oklahoma Territory, where his father was a grain buyer. From 1921 to 1924, Keith attended Northwestern State Teachers College. In addition to his studies, he wrote for daily and weekly newspapers in Watonga, Alva, Cherokee, and Enid, Oklahoma. After transferring to the University of Oklahoma, he became sports editor for the Oklahoma Daily, the student newspaper. Many of his columns dealt with the history of Sooner athletics, emphasizing the individuals as well as their accomplishments. Some of these columns were picked up by daily newspapers throughout the state.

Keith's experiences as a long-distance runner for the University of Oklahoma taught him the philosophy he later put in the mouth of the character Sergeant Pete Milholland: "You can always go farther than you think you can." In 1928 Keith placed first in the indoor mile and two-mile races at the Missouri Valley Conference championship meet. He also ran the anchor mile on the University of Oklahoma's All-American distance medley relay team.

After graduating with a bachelor's degree in history in 1929 and working briefly as an assistant to a grain buyer in Hutchinson, Kansas, Keith returned to the University of Oklahoma as sports publicity director, a job he held until his retirement in 1969.

On August 30, 1931, Keith married Virginia Livingston. After the birth of their two children, John Livingston and Kathleen Ann, Keith continued to study Oklahoma history, receiving his master's degree in 1938. Research for his thesis, "Clem Rogers and His Influence on Oklahoma History," provided some of the material for his first book, a biography of Clem's famous son, the humorist Will Rogers. In interviews with Civil War veterans, Keith also gathered much of the information he eventually used in Rifles for Watie. Published in 1957, the novel was awarded the Newbery Medal in 1958. Keith has also received the Western Writers of America Spur Award (1975) and two Western Heritage Awards (1975 and 1979).

Since his retirement, Keith has pursued his interest in long-distance running, University of Oklahoma athletics, and writing. In 1973 he set the U.S. Masters national records in the two and three-mile runs, and in 1974 he set the record for 10,000 meters. His most recent book is Forty-Seven Straight, a history of the University of Oklahoma football program during the tenure of head coach Bud Wilkinson. Keith's manuscripts are housed at Northwestern State College library and the University of Oklahoma library.