A population study was conducted on 580.5 feet of Hunt Creek, a tributary of the Thunder Bay River, in Montmorency County, Michigan. Hunt Creek was open to public fishing over its entire length during the 1940 trout season. A combination of stream diversion, blocking and seining, and finally poisoning with rotenone, enabled the investigators to obtain a capture of all fish in 0.131 acres of stream. The total fish population consisted of 605 brook trout weighing 12.36 pounds, and 188 muddlers weighing 1.27 pounds. From these data it was computed that Section C of Hunt Creek was supporting 4,619 brook trout (weight, 94.40 pounds) and 1,435 muddlers (weight, 9.68 pounds) per acre. Of the 605 brook trout captured, 2.3 per cent (14) were legal-sized (7 inches, total length or longer); 22.0 per cent (133) were between 4 and 6.9 inches; and 75.7 per cent (458) were between 2 and 4 inches long. Two and one-half times as many legal-sized brook trout were captured in the deeper portion of the area as in the shallower region. Analysis of the data indicates that seining as a method of capture, even in blocked-off portions of trout streams, has an efficiency of no more than about 80 per cent, as far as number is concerned.