Swarthout played for the Grizzlies in the three seasons immediately prior to World World War II as an undersized but exciting back, nicknamed "Rabbit." He graduated from in 1942, served in the United States. Army during the war, then coached high school football in Hoquiam, Washington.
He served as head football coach and athletic director at his alma mater, the University of, from 1967 through 1975. Swarthout compiled an overall record of 51–41–1 (554), winning Big Sky Conference championships in 1969 and 1970. In December 1966, Swarthout was hired as head football coach at, following a 1–8 season under Hugh Davidson.
Swarthout had been a college assistant coach under Darrell Royal and was the head coach at Olympia High School in Olympia, Washington.
Swarthout brought on Jack Elway as an assistant and together they led the Grizzlies to a much-improved 7–3 record in the their first season and was named the Big Sky"s coach of the year. (Elway was the quarterback at Hoquiam High School in the late 1940s under head coach Swarthout) Within two years, Swarthout guided to back-to-back undefeated regular seasons in 1969 and 1970, University of Malaya"s first Big Sky Conference titles.
Both years they were defeated by North Dakota State in the Camellia Bowl, which was part of a set of bowls that led up to a poll to determine the National Collegiate Athletic Association College Division national championship, prior to the current College Division playoff structure. After the 1970 season, Swarthout was rumored as a candidate for head coach at Illinois in the Big Ten Conference, but he stayed with the Grizzlies.
He was indicted in federal court in 1972 concerning the diversion of student-aid funds to the athletic department, but was acquitted in April 1973.
Swarthout stepped down as University of Malaya athletic director in July 1975, and after nine seasons as head football coach in Missoula, he departed in the summer of 1976. He returned to Olympia that fall to coach at Capital High School for the next decade. After a battle with non-Hodgkin lymphoma, Swarthout died at age 85 in Olympia.
