There are
719 mi
from Thornton, CO to Sunland Park, NM
That's the driving distance. It would take 12 hours 31 mins to go from Thornton, Colorado to Sunland Park, New Mexico.
The flight distance (direct flight from Thornton, CO to Sunland Park, NM) is 564.88 mi.
719 mi = 1,157.39 kms