Frost line depth in Vigo County, IN

How deep the ground freezes in Vigo County, IN

21 in. Dig to 21 in, just below the frost. Nearest NOAA station: Terre Haute Indiana State, 2.9 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.