The son of Ole Andrew and Gunhild Sandnes Gellein was born May 15, 1911, in Milnor, North Dakota. As a youngster, he was raised on an Idaho ranch and graduated from high school at the age of 16. He earned a bachelor's degree and master's degree in mathematics from Southeastern Oklahoma State University (1932) and Oklahoma State University (1939), respectively. He minored in accounting while earning the master's degree. He completed the coursework for the Ph.D. in accounting at the University of Texas in Austin but he did not complete the requirements necessary for the degree. He was certified as a CPA in 1952 (Colorado).
His early working career included being a cowboy, running a filling station, and being a teacher (1932-33) and a principal (1934-48) at a high school in Fox, Oklahoma. He taught accounting at Kansas State University for four years (1939-43) before joining the United States Naval Reserve during World War II. During his tenure with the navy from 1943 to 1946, he taught aerial navigation in Florida, Oklahoma, and California. After the war, he spent six years (1946-52) at the University of Denver; the first four years he taught accounting and the last two years he served as treasurer of the university.
In 1953 he joined the firm of Deloitte Haskins & Sells after being recruited by Hall of Fame members John W. Queenan and Arthur B. Foye. He became a partner in 1955. While with the firm, he started (1953) its Research Department. He was located in the firm's executive office in New York and in practice offices in New Jersey and Michigan where he supervised the audit of General Motors. He was with Deloitte Haskins & Sells for 21 years before retiring in 1974. He was national director of accounting and auditing at the time of retirement.
He was active in professional organizations, particularly the AICPA. He was a member of the AICPA's Committee on Statistical Sampling (1956-61; chairman 1958-59) and the Committee on Auditing Procedure (1961-67). He chaired the Committee on Relations with the SEC and Stock Exchanges (1968-71). He also served as a member of the AICPA's Study Group on the Objectives of Financial Statements (1971-73); Accounting Literature Awards Committee (1972-75); Board on Standards for Schools of Professional Accounting (1974-75); and Awards Committee (1975-78). In 1969-1970 he was vice president of the AAA. He also holds membership in the Colorado Society of CPAs, and the New York State Society of CPAs. He has served as a member of both the Accounting Principles Board (1971-73) and the Financial Accounting Standards Board (1975-78). In 1974, he received the AICPA's Gold Medal Award for distinguished service, and in 1985 he was honored as a Distinguished Alumnus at Southeastern Oklahoma State University's Homecoming. He is a member of Beta Alpha Psi and Phi Kappa Phi.
He has written numerous articles for professional journals. He authored the AICPA's Accounting Research Study No. 14, "Accounting for Research and Development Expenditures" with Maurice S. Newman (1973). He also served as a member of AICPA's Project Advisory Committee for Accounting Research Study No. 1, "The Basic Postulates of Accounting" authored by Hall of Fame member Maurice Moonitz.
On June 15, 1928, he married Nettie Belle Harshman whom he met in high school; they have one child. He has lived in 16 states and has gone to Nairobi and Bangkok to see his grandchildren. In his leisure time he enjoys writing, gardening, and golfing.