Frost line depth in Carlton County, MN
How deep the ground freezes in Carlton County, MN
63 in. Dig to 63 in, just below the frost. Nearest NOAA station: Cloquet, 9.9 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.