Leon Claude Covell was born at Middleville, New York on 2 December 1877 and was raised in Washington, D.C. where he attended George Washington University. He entered the U.S. Revenue Cutter Service as Cadet in June 1900 and received his training aboard the School of Instruction vessel Chase based at Curtis Bay, Maryland. He graduated from the program and received his commission as Third Lieutenant on 30 June 1902.
After serving in various junior officer postings on board cutters of the fleet he gained his first command in 1914. The cutters under his earliest command included the Snohomish, based at Seattle, Washington and the Unalga at Alameda, California between 1914 and 1917. During World War I he also commanded the cutter Mackinac and then was the Navigator on the cruiser USS Minneapolis while she was operating as a convoy escort in the North Atlantic. He then served as the Executive Officer of the New York Division. Between 1920 and 1930, his commands included the cutter Gresham out of Norfolk, Virginia, the cutter Tahoe in the North Atlantic, the cutter Shoshone in Alaska and command of the Coast Guard’s Bering Sea Patrol fleet.
He served as the Assistant Commandant from December 1931 until his retirement on 1 January 1942. He was recalled to active duty in June, 1943, and was given command of the Coast Guard Training Station at Manhattan Beach, New York. He retired again in April, 1945. He rose to the rank of Rear Admiral on 24 May 1939 and was promoted to Vice Admiral while later in retirement (Tombstone promotion).
His active-duty career spanned a total of 45 years, including 22 years service at sea.
He crossed the bar on 20 November 1960 and was buried in the Fort Rosecrans National Cemetery in California. He was preceded in death by his wife, who passed away on 10 July 1955. They were survived by their son, Leon Claude Covell, Jr.