Frost line depth in Rolette County, ND
How deep the ground freezes in Rolette County, ND
73 in. Dig to 73 in, just below the frost. Nearest NOAA station: Belcourt Keya Radio, 6.5 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.