Ask about anyone what rifles the beaver trappers and mountain men carried with them and you will be told they carried Hawken guns made by Sam and Jacob Hawken in St Louis.
I thought so too. But a little more reading and google searching turned this up. I also stated in another thread on the sister forum that I also suspected that those eastern men who came west probably brought their eastern rifles with them and used them in the mountains. It looks like my guess was correct. And there were many more non Hawken rifles in the mountains than you would think. This article makes it sound like Hawkens were sort of scarce by comparison. Its a good read. Hope you like it.
http://traditionalmuzzleloader.com/index.php/rifles
This rifle maker also supplied a lot of the rifles used by trappers and explorers and supplied trade rifles to the government. Henry lemon supplied a huge amount of rifles for a long period of time until his death and the closing of his plant.
http://americansocietyofarmscollecto...051_Hanson.pdf