First documentation to place him in the Valley is a rebaptism in the Salt Lake 17th Ward on 19 December 1857. His name is recorded as William R. McLean and his birth date was recorded at the time of that ordinance. Further research is needed to narrow the year of his travel and identify the name of the company with which he traveled.
Family Search has his name listed as William Johnston McLean. His christening record lists his name as William Johnston McLean and his birth date is listed as 7 August 1822. Seventeenth Ward records has the year listed 1823.