First, let me state that I have a Flintlock and enjoy shooting it on a very regular basis. It's not high priced, has its own problems, and yet I have my fun with it. Being more interested in the fur trade then in the Revolutionary war period as far as firearms used, I did believe that the trappers probably carried a lot of flintlocks. Apparently, that might not be so. I also subscribe to a magazine called The Backwoodsman. The last one, (July August), had an interesting article entitled, so just what gun did the mountain men carry? Written by David Langerman. From this very interesting article I learned a few things, mainly the most of the fur trappers probably carried percussion's. As far as research goes, from start to finish, the Hawken rifles were percussion. It also mentions that caps cost $.80 per thousand and were also waterproof. One of the things mentioned, was that by 1820, Cap lock rifles had become quite popular and there was a growing industry that converted flintlocks into cap locks. We do know the first fur trade rendezvous was held in 1825. I'm sure there were flintlocks present, but apparently there was a growing usage of cap locks.
Perhaps others get this same magazine, it's quite an interesting article. If nothing else it makes for a good discussion.
Squint