Frost line depth in Yellowstone County, MT

How deep the ground freezes in Yellowstone County, MT

40 in. Dig to 41 in, just below the frost. Nearest NOAA station: Huntley Exp Stn, 1.8 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