Mark-and-recapture estimates of the number of hatchery-reared brook trout (Salvelinus fontinalis) have been made each April and October since October 1956 in Ford Lake (10 acres) and Hemlock Lake (6 acres), at the Pigeon River Trout Research Station, Vanderbilt, Michigan. Fish were captured by angling, by trapping with wire traps, and by shocking with direct current at night with underwater lights. A permit-type creel census insured a nearly complete record of the catch.