ary S. Larson was born in Salt Lake City, Utah. He attended the University of North Carolina as a Morehead Scholar and received a B.A. degree in Mathematics in 1975. He is a member of Phi Beta Kappa. Mr. Larson then served as a foreign missionary in Helsinki, Finland. In 1980, he received his law degree from the J. Reuben Clark Law School, Brigham Young University, with honors.

Mr. Larson is a member of the Idaho State Bar and the American Bar Association, including its Sections on Real Property, Probate and Trust Law and Taxation. He is a former president of the Eastern Idaho Estate Planning Council, the Advisory Board of the Good Samaritan Center of Idaho Falls, the Advisory Board of the Salvation Army of Idaho Falls, the Bonneville County Board of Community Guardian, the Region Six Affordable Housing Task Force and the Idaho Falls Kiwanis Club. He has also been a board member of the United Way of Idaho Falls and Bonneville County, the Rocky Mountain Venture Group and the City Council for the City of Ucon. Mr. Larson has made frequent public presentations regarding wills and probate, estate planning, and employment relations. His practice is principally involved with tax and estate planning, commercial transactions and litigation.

Mr. Larson and his family of nine are involved in Scouting, sports, charitable and religious activities. His wife Louise Larson is a school teacher.