Frost line depth in Blaine County, MT

How deep the ground freezes in Blaine County, MT

46 in. Dig to 47 in, just below the frost. Nearest NOAA station: Ft Belknap 2 Sw, 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.

Code depth · Snow