There are
1,570 mi
from St George, UT to Dekalb, IL
That's the driving distance. It would take 1 day 3 hours to go from St George, Utah to Dekalb, Illinois.
The flight distance (direct flight from St George, UT to Dekalb, IL) is 1,359.66 mi.
1,570 mi = 1.61 kms