Thomas Gist (b. 1735), third son of Christopher Gist, was listed as an ensign on a return of the Virginia Regiment of 12 May 1758. Gist reached the rank of lieutenant before the Virginia Regiment disbanded in 1762. After his father's death in 1759, Thomas had taken over his plantation, which he called Monongahela, at the foot of Laurel Hill, in the vicinity of present-day Mount Braddock, Pennsylvania. GW dined there during his travels to his western lands in the fall of 1784 (see Diaries, 4:18).

In September 1772, GW paid 12 shillings to Charles Turner (died c.1780) for repairs he made to Gist's watch. Gist repaid GW in February 1774 (see Ledger B, 59, 60, 105).