You might find this interest'n,.....
Another transformation in manners signaled the seemingly trivial difference between a two-pronged and a three-pronged fork. Before 1830, virtually all New Englanders were still eating with their knives in the characteristic American fashion. That is, they used their forks--the traditional two-pronged variety--only to hold meat for cutting, and brought food to their mouths with their knives. This was not a custom that pleased English commentators. Visiting in 1828, Margaret Hall complained that "it goes rather against one's feelings to see a prettily dressed, nice-looking young woman ladling rice pudding into her mouth with the point of a great knife," or, even worse, to see a girl "feeding an infant of 17 months in the same way." Gradually such criticism and the continued drawing power of upper-class English ways were beginning to have an effect.
The 1830s found a number of genteel American families adopting the European style, in which the fork was used for conveying food and the knife only for cutting. To accomplish this they needed not only to abandon their traditional use of the knife but to reject the customary two-pronged fork as well. Its widely separated tines made an impractical implement for gracious dining; the chosen utensil for those who wished to eat fashionably became the three- or four-pronged fork, whose additional tines made it far easier to use in the new style.
I think the common use of a fork wouldn't be seen in a fur trappers camp, as those fellas were "heading west" at the time the current European-style of "eat'n" was just starting to take place in eastern America.
YMHS
rollingb