Frost line depth in Wood County, WI
How deep the ground freezes in Wood County, WI
48 in. Dig to 48 in, just below the frost. Nearest NOAA station: Wisconsin Rapids Alexander Fld, 12.2 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.