United States, Minnesota, Marshall, Thief Lake Wildlife Management Area. Thief Lake Wildlife Management Area; 3.6 mi. N of the jct. of Rte. 6 and Rte. 89 (on the E side of Rte. 89). T158N, R39 Thief Lake Wildlife Management Area; 3.6 mi. N of the jct. of Rte. 6 and Rte. 89 (on the E side of Rte. 89). T158N, R39W, Sec. 30.. 158N 39W 30