There are
620 mi
from Clarksville, TN to Ankeny, IA
That's the driving distance. It would take 12 hours 2 mins to go from Clarksville, Tennessee to Ankeny, Iowa.
The flight distance (direct flight from Clarksville, TN to Ankeny, IA) is 490.70 mi.
620 mi = 998.11 kms