It depends on your exact route, but the approximate driving distance by road is 807 miles.
About 445 miles.
1140 miles.
About 590 miles.
776 miles
About 1,142 miles / 1,840km
It is 438 miles according to Google Maps.
The driving distance from Denver CO to Missoula MT is 898 road miles.
Right around 1,000 miles.
About 587 miles
Which Grand Junction?
The driving distance between Missoula, MT and Goldendale, WA is approximately 365 miles.
The driving distance from Phoenix AZ to Missoula MT is 1,181 road miles - about 19 hours driving time.