Effects of a flies-only regulation on angling and on fall populations of wild brook trout were tested on 5,000 feet of Hunt Creek, Montmorency County, Michigan. Complete angling records and population estimates for the period 1949-54, when all sections were fished under normal state regulations, were compared with records for the period 1955-59, when sections Z and A were fished under a flies-only regulation, and B and C continued under normal rules. Yearly totals for angling load, catch, angling quality, pounds of trout creeled, small trout released, and postseason (fall) population estimates were compared. Averages for the 5 years after the lure regulation was changed were compared with averages for the years before the change for both Z and A and the B and C controls. Also, annual totals for Z and A were related to corresponding annual totals for B and C to provide ZA/BC ratios for before-and-after comparisons.