Frost line depth in Todd County, MN
How deep the ground freezes in Todd County, MN
65 in. Dig to 65 in, just below the frost. Nearest NOAA station: Long Prairie, 7.1 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.