Well, I’m a bit late on this one. I’ve been playing in the woods and in my shop making stuff.
IMO, Osage is very special bow wood, toughness and performance is the best. But, there are a lot of other bow woods that will work, especially for a learning process.
NW Montana is an ok place but not known for quality bow wood. However, good bows can be made from ServiceBerry (June Berry), Choke Cherry, Mountain Maple and our local Yew. There are a few pockets of bow quality Yew scattered around NW Montana but will be as hard to find as a big bull elk. All of these woods will make a good bow but will be a challenge for a beginning bowyer. Fruit trees can make bows, I am currently working on a bow using a stave from a plum tree I cut last summer. It is full of knots with a couple of twists but holds promise.
If you have wood working experience and can communicate with wood and see and hear what it is telling you then the wood itself will guide you to a bow, if there is a bow in there. Obviously you will not reach that level without some experience.
For the first bow or two,depending on financial considerations, I would recommend purchasing a good stave from someone that offers quality Osage staves. That will up your odds of success.