There are
1,790 mi
from Thornton, CO to Mamaroneck, NY
That's the driving distance. It would take 1 day 8 hours to go from Thornton, Colorado to Mamaroneck, New York.
The flight distance (direct flight from Thornton, CO to Mamaroneck, NY) is 1,636.46 mi.
1,790 mi = 1.61 kms