Frost line depth in Lake County, MT

How deep the ground freezes in Lake County, MT

30 in. Dig to 31 in, just below the frost. Nearest NOAA station: Polson, 5.4 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.

Code depth · Snow