Frost line depth in Valley County, MT

How deep the ground freezes in Valley County, MT

55 in. Dig to 55 in, just below the frost. Nearest NOAA station: St Marie, 8.2 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