He graduated from Big Piney High School and then attended the University of Wyoming, where he received a degree in agriculture. He gained the rank of sergeant while serving in infantry during World War II.

He had seven children, six of whom graduated from Big Piney, along with eight grandchildren who graduated from Big Piney.

Mr. Mickelson was especially active politically, having served six years as the Sublette County Representative in the Wyoming House. He gave much of his time to local, county and state programs. He was Past Master of Big Piney Masonic Lodge 47, was Sublette County's representative for seven years on the University of Wyoming Alumni Board, served twelve years and presided as President on year on the University of Wyoming Board of Trustees, was a Director on the First National Bank of Kemmerer, and served as Chairman of the First Wyoming Bank of Big Piney.