When I lived in Montana in the 70s and 80s I hunted and field dressed about 15 deer and a couple elk with a locking Case pocket knife with a 3 inch blade.  I also carried a 5 inch hunting knife that I mostly used to split the rib cage and pelvis "H" bone. The sheath knife was forged by an old Finn, Carl Ruana of Bonner Mt., from Studebaker pickup leaf springs.  Very soft and tough steel--easy to sharpen, but very obtuse angle so you could bash it with a rock as a hatchet...