There are
1,036 mi
from Hereford, TX to Ammon, ID
That's the driving distance. It would take 19 hours 3 mins to go from Hereford, Texas to Ammon, Idaho.
The flight distance (direct flight from Hereford, TX to Ammon, ID) is 786.62 mi.
1,036 mi = 1,666.52 kms