Mr. Boone, a native of Iowa, got an early start with horses, having had a pony to share with his brother in their daily commute to and from a one-room schoolhouse, according to accounts in an Almanac story from 2005 and from his family.
In 1940, after graduating from Iowa State University with a degree in agricultural economics, he took a job with Cargill, the Minneapolis agribusiness giant. Following the attack on Pearl Harbor, Mr. Boone joined the Naval Air Corps.
Mr. Boone married Nancy Goulet in 1946 and returned to Cargill, where he rose to the position of vice president of the oil seed processing business for the Pacific Rim. He traveled frequently with his wife to the Southwest Pacific, stopping frequently at Maui, one of their favorite places.
During more than 52 years in Woodside, Mr. Boone volunteered as board member of the Woodside Trail Club, as chair of the Woodside's Trails Committee, and as president of the Woodside Community Foundation. He was a longtime member of the Mounted Patrol, which has its facilities in Woodside. The Mounted Patrol elected him a captain in 1974 and named him Outstanding Horseman-Citizen of the Year in 1994. In 2005, the town named a riding trail after Mr. Boone.
Mr. Boone is survived by daughters Kathy Boone, Betsy Harms and Bonnie Boone-Altshuld and six grandchildren. In lieu of flowers, the family asks that donations be made to: The "Howard D. Boone Memorial," MPSMC Foundation, 521 Kings Mountain Road, Woodside, CA 94062.