Truckstop guide?

The Ultimate Truck Parking Guide is a good book to get. A little hard to come by, but covers the interstates well with additional parking besides just the truck stops: Walmart's, restaurant's, hotel's, etc. that allow parking. It even tells you where some wide spots along side the roads are.
It also has several U.S. highway's information.
The newest edition looks a bit bigger even than my Third Edition.
Truckerpath is the app I use.
Between the two, I can find something somewhere.
If nothing else, satellite view and just looking up 'truck stops' works in a pinch in the more out of the way places. The biggest problem with that is that a lot of car dealers and truck accessory places pop up as well.

 

The ultimate truck parking guide, 4th edition