Priest lake idaho

To cross back into the U.S. from Canada you will need valid passports.

We stayed there a couple of years ago. As I remember we had a site in the 50's and it was really hard to back into because of trees, bushes, etc. Hope your reservations are closer to the lake (in the 100's), those sites were more open. It's beautiful there, kinda in the middle of nowhere. Others have given good advice on entering Canada

Priest Lake is a gorgeous area. There is a Priest Lake State Park Facebook page, as well as a lot of other info to be had by Googling the various towns in the area.

As far as crossing into Canada, if you are taking a dog with you, make sure you have up to date verification of its vaccinations. Also check with the Canadian website http://www.inspection.gc.ca/food/information-for-consumers/travellers/what-can-i-bring-into-canada-/eng/1389648337546/1389648516990
To verify what you can and cannot bring in.

Passport is required for entry to Canada and back in to U.S.