Frost line depth in Wirt County, WV
How deep the ground freezes in Wirt County, WV
21 in. Dig to 21 in, just below the frost. Nearest NOAA station: Creston, 7.1 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.