There are
2,100 mi
from La Mesa, CA to Clarksville, IN
That's the driving distance. It would take 1 day 12 hours to go from La Mesa, California to Clarksville, Indiana.
The flight distance (direct flight from La Mesa, CA to Clarksville, IN) is 1,789.84 mi.
2,100 mi = 3,379.50 kms