There are
827 mi
from Hereford, TX to Hannibal, MO
That's the driving distance. It would take 14 hours 50 mins to go from Hereford, Texas to Hannibal, Missouri.
The flight distance (direct flight from Hereford, TX to Hannibal, MO) is 694.12 mi.
827 mi = 1,330.34 kms