Frost line depth in Otero County, NM
How deep the ground freezes in Otero County, NM
19 in. Dig to 20 in, just below the frost. Nearest NOAA station: Cloudcroft, 23.4 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.