Will be traveling and camping in Montana and Idaho with some side trips into Canada. Want to have a shotgun along. Will it be allowed in Canada?

yes :

when you ll fill out the paper just tick the case in transit and you re good to go.

but check before regulations : because some campgrounds and areas forbid the own and of course the use of a firearms even in his own case locked ....

http://www.rcmp-grc.gc.ca/cfp-...visit-visite-eng.htm

http://www.rcmp-grc.gc.ca/cfp-...mulaire/pdfs/909.pdf

Willieb, go to my website and print the gun forms off. Fill them out and don't sign your name to the bottom untill asked by the customs officer. It is easy to bring guns across the border this way and does not take long to fill the papers out.
Have fun!
http://www.deansoutdoor.com/

Make sure you get a slip from US customs showing you own the gun before you go over into Canada with it.