[1] Born in Mobridge, South Dakota, Carrigan received a Bachelor of Philosophy from the University of North Dakota in 1953, a Juris Doctor from the University of North Dakota School of Law in 1953, and a Master of Laws from New York University School of Law in 1956.

[2] On June 1, 1979, Carrigan was nominated by President Jimmy Carter to a new seat on the United States District Court for the District of Colorado created by 92 Stat.

He assumed senior status on October 10, 1994, and served in that capacity until his retirement on August 19, 1995.

[2] Following his retirement from the bench, Carrigan served as an arbitrator for the Judicial Arbiter Group in Denver.

[1] Carrigan died on August 15, 2014, in Boulder, after suffering a series of strokes.