Frost line depth in Saline County, NE
How deep the ground freezes in Saline County, NE
35 in. Dig to 35 in, just below the frost. Nearest NOAA station: Friend 3e, 10.7 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.