Frost line depth in Eau Claire County, WI
How deep the ground freezes in Eau Claire County, WI
54 in. Dig to 55 in, just below the frost. Nearest NOAA station: Augusta Rs, 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.