There are
2,767 mi
from Rockville, MD to Lathrop, CA
That's the driving distance. It would take 2 days to go from Rockville, Maryland to Lathrop, California.
The flight distance (direct flight from Rockville, MD to Lathrop, CA) is 2,365.34 mi.
2,767 mi = 4,453.09 kms