There are
2,034 mi
from Mt Prospect, IL to Seatac, WA
That's the driving distance. It would take 1 day 11 hours to go from Mt Prospect, Illinois to Seatac, Washington.
The flight distance (direct flight from Mt Prospect, IL to Seatac, WA) is 1,712.65 mi.
2,034 mi = 3,273.41 kms