Frost line depth in Lake of the Woods County, MN
How deep the ground freezes in Lake of the Woods County, MN
71 in. Dig to 72 in, just below the frost. Nearest NOAA station: Baudette Intl Ap, 14.3 mi.
Your building department sets the legal frost line depth (IRC Table R301.2(1)); footings must go below it (R403.1.4.1). Call them before you dig.