There are
1,589 mi
from Gaithersburg, MD to Rapid City, SD
That's the driving distance. It would take 1 day 4 hours to go from Gaithersburg, Maryland to Rapid City, South Dakota.
The flight distance (direct flight from Gaithersburg, MD to Rapid City, SD) is 1,380.88 mi.
1,589 mi = 2,557.37 kms