Gayle McKeachnie was born in Vernal, Utah and attended school there. He is married to Kathlene Argyle of Spanish Fork. He received a B.A. Degree from the College of Southern Utah. At College he was a member of the basketball team, President of the Student Senate, and Student body Vice President. He was recognized as the Outstanding Junior Student and the Outstanding Senior Student of his class. He received his J.D. Degree from the University of Utah College of Law and was honored by selection to the Law Review and Order of the Coif.

After two years with a Salt Lake City Law firm he and Kathlene moved to Vernal and opened a law practice. His law practice has included service as a county and city attorney and clients have included, local governments, irrigation companies, individuals, businesses, and state agencies in school trust land matters. In Vernal he taught classes as an adjunct professor for Utah State University in the areas of political science, business management, business and constitutional law. He has also taught as an adjunct professor at the BYU, J. Reuben Clark Law School. He served four terms in the Utah House of Representatives, where he was at various times chairman of the Rules Committee, House Parliamentarian and Majority Whip. He has been a member of the Utah State Bar Board of Commissioners, the Utah State Board of State Lands and Forestry, the KUED Friends Board, is a past President of the Vernal Chamber of Commerce and served twice as the chairman of Governor Leavitt's transition team for the Department of Natural Resources and in the same position for Governor Jon Huntsman in 2004. He served as a member and as the chairman of the Utah State Constitutional Revision Commission, and as a member of the Utah Foundation Board of Trustees. He served as a member of the Utah State University Board of Trustees where he was chairman, and he was also a member of the Uintah Basin Applied Technology College Board, and the Utah Judicial Conduct Commission by appointment of the Utah Supreme Court. He was given the Southern Utah University Distinguished Alumni Award in 1995 and was named the Distinguished Lawyer of the Year in 1997 by the Utah Bar Association.

He and Kathlene are the parents of 7 children and 22 grandchildren and live on, operate a small farm and ranch at Vernal.