Rest area overnight Montana and Idaho

n7bsn has it right as far as I can remember, the RA is near Superior which is about 50 some miles west of Missoula. There's a RA in Idaho just west of Coeur d'Alene but it's right next to the freeway and therefore noisy. A favorite of ours is in WA about halfway between Moses Lake and Spokane, real quiet since if's about 1/4 mile off the freeway; don't know if you can spend the night there or not. Check your maps for WA and ID RA's amd the list noted by DesertHawk above for MT RA's is a good source for that state.