There are
809 mi
from Clarksville, TN to Harker Heights, TX
That's the driving distance. It would take 14 hours 31 mins to go from Clarksville, Tennessee to Harker Heights, Texas.
The flight distance (direct flight from Clarksville, TN to Harker Heights, TX) is 700.27 mi.
809 mi = 1,301.15 kms