Each state & province has different laws, so you can't assume anything.
Forget boondocking in California coastal areas. Basically each city has ordinance forbidding RV overnight stay and they force Walmarts to do that as well.
The practice seems to extend to Oregon, Yukon and who knows how many other places.
But on our drive to Alaska only few rest areas had "no overnight stay" signs, so we could pull over at any convenient area and sleep well. Canada Information Centers have dump stations and water faucet, so that was easy.
Than states like AZ allow boon-docking basically everywhere.
