There are
895 mi
from Hereford, TX to Marshalltown, IA
That's the driving distance. It would take 15 hours 47 mins to go from Hereford, Texas to Marshalltown, Iowa.
The flight distance (direct flight from Hereford, TX to Marshalltown, IA) is 715.84 mi.
895 mi = 1,439.80 kms