Tony's question seems right on the money. Where in Northern Idaho are you going to be traveling? I have read several pieces on wolves in Northern Idaho while working on my newsletters. I did a quick google search and found a few on them. As to other big critters, like Bison/Elk/Moose, I am not really sure.

Here are some links about wolves. The first link is a bit older. The 2nd link though, which talks about wolf management seems to corroborate some of the data though.