There was a brief discussion of this over at the Muzzleloading forum some years back, and Spence10 found a couple of references to pistols in the hands of travelers contained in Running Mad for Kentucky, including a guy that was armed with, IIRC, a sword, two braces of pistols, and a rifle; another guy who was mounted and armed with a brace of pistols and a sword but no longarm; and a group of travelers in which the women were armed with pistols and stood guard at night with their husbands.
From this we can conclude that they were present out along the transappalachian frontier, at least from the Revolutionary period onwards. I think that all those references came from the 1776-1794 period, in which the Whites and Indians were at war, and none of them were folks out hunting or engaged in everyday tasks - they are all (as the title suggests) accounts of people traveling from East of the Appalachians into Kentucky.
I own a copy of this book, but it is currently in storage.