Hi Jody, you guys are in for a great adventure. Spring bear hunting can be a ton of fun! Idaho or Montana, both are great choices. Here’s my 2 bits worth of free advice
First thing, you’ve already started down the right path. Research and planning are part of the fun, at least to me, and the better job you do on the research the more enjoyable and successful your hunt will likely be. There is a lot of excellent information available to you on the Idaho Fish & Game website. I’ve never hunted bear in Montana, but I’m sure they have pretty much the same info available as Idaho.
For spring bear, timing is pretty important. Depending on the specific area you choose to hunt, what the winter has been like and the current weather, a week one way or the other can make or break your hunt. My advice would be don’t go too early.
There are a few exceptions, but speaking in general terms the spring bear season in Idaho runs from April 15 - June 15. Some units are open ‘til June 30 and a few close the end of May. Late May / early June is generally about the best bet. It depends a little on the year, but hunting before May 15 is a total crap shoot. If you are local like I am, no big deal, go later if the weather sucks.. Coming from across the country, big problem! Your hunt is toast.
Also keep in mind Memorial Day. Looks like it falls on May 27 in 2019. In the spring much of the high country is inaccessible. Most places you are going to be able to get to in late May will have weekend campers out for the holiday weekend. I would avoid the 23rd thru the 29th unless you are getting dropped by bush plane in a remote area. Trust me, you won’t have a good experience on Memorial Day weekend in most places.
The week before Memorial Day can be good, but still prone to getting screwed by weather. Immediately after Memorial Day is my favorite. Roads are opening up and more access to the back country will help your mobility greatly. Understand though, there is much of the mountain country you will have a difficult time accessing much before July 4th. Mountain passes just don’t open up before then.
Just a bit about Idaho and Montana bears. There are areas that have a good number of color phase bears and other areas that have none. If you care about something other than black, do your homework!
A good bear in Idaho is a 200 pound bear. A 300 pound bear is a really big bear. Yes, there are some bigger bears around, but just like big mule deer and big elk they are damn tough to find! Most bear that get shot are less than 200 pounds. Be very happy if you shoot a bear. Count yourself incredibly lucky if you get one over 200 pounds. If a big bear is a priority, hire an outfitter.
Bear are really difficult to judge. I have shot a few and looked at a lot! Probably several hundred. I still have trouble field judging bear, especially at a distance through binos or a spotting scope. Once again, do your homework as best you can. I would watch a bunch of videos.
Feel free to drop me a PM if you have some specific questions. Happy to answer them if I can.
Good luck and have fun!