Do we know how many fur trappers and guides in the early west had rifles made by the Hawken shop? I'm not sure about this one.

Some of them surely did carry Hawken rifles, like Jim Bridger, but I don't know if most of them did. The Hawken did have some advantages, compared to a typical Kentucky rifle circa 1820. The Kentucky style had been graceful, with a very long barrel that was tapered and flared. It had a rather narrow wrist, and the wood at the fore end, under the barrel, was quite thin. It was susceptible to damage at these points- and guns get used outside, dropped on rocks, etc. so it is very common to find the surviving "Golden Age" Kentucky rifles with missing wood at the fore end and cracks through the wrist. By 1830, the caliber of the typical Kentucky had also shrunk to around .36 or .32, as the big game in the east had gotten pretty scarce, the barrels had become straight ( as making them became generally more industrialized) but were still pretty long, around 40 inches. The Hawken shop made something a bit better suited to the west. It was founded by Jacob, who had experience at the Harper's Ferry Armory. Military guns had to be somewhat rugged, and the rifle that was created in the Hawken shop was more rugged than a typical Kentucky rifle. The barrel was a little shorter and more compact, of a larger caliber that would work for large game. Like the 1803 Harper's Ferry rifle, it had a half-stock for durability. The breechplug had a long tang, to reinforce the wrist. At some point ( I am not quite sure when) there was a hook breech as well, which made it easier to take apart and clean the gun- and a black powder gun will always have to be cleaned. And, the gun was made in St Louis: which was the stepping-off place for plenty of trade with the west.

However, after some years the Hawken shop by no means was alone in making what are now called Plains Rifles. The Leman shop in Lancaster PA was quite large at this time as well, and with economies of scale in the later 1830's produced quite a lot of them, certainly more than the Hawken shop ever could make and almost certainly cheaper. Leman made a lot of simple rifles for the Indian trade, also. Perhaps Jim Bridger was proud of his Hawken, but a large number of people heading west brought Leman rifles with them instead, and a lot of the Native American trappers might well have carried a Leman rifle like this one.