Russell says "I killed two Bulls which came in good time after living upon Dried meat all winter" which reiterates that mountaineers lived on a carnivore diet.
Journal of a Trapper
20th of Octr. we started to hunt Buffaloe and make meat for the winter. The party consisted of 15 men. We travelled to the head of the Jefferson fork of the Missouri where we Killed and dried our meat from there we proceeded over the mountain thro. "Cammas prarie" to the forks of Snake river where most of the party concluded to spend the winter 4 of us however (who were the only Americans in the party) returned to Fort Hall on the 10th of Decr. We encamped near the Fort and turned our horses among the springs and timber to hunt their living during the winter whilst ourselves were snugly arranged in our Skin lodge which was pitched among the large Cotton wood trees and in it provisions to serve us till the Month of April. There were 4 of us in the mess One was from Missouri one from Mass. one from Vermont and myself from Maine We passed an agreeable winter We had nothing to do but to eat attend to the horses and procure fire wood We had some few Books to read such as Byrons Shakespeares and Scotts works the Bible and Clarks Commentary on it and other small works on Geology Chemistry and Philosophy - The winter was very mild and the ground was bare in the Valley until the 15 of Jany. when the snow fell about 8 inches deep but disappeared again in a few days. This was the deepest snow and of the longest duration of any we had during the winter On the 10th of March I started again with my old companion Elbridge We travelled from the Fort on to the Blackfoot near the foot of the Mountain where the ice being broke up we set some traps for Beaver On the 15th we tried to cross the mountain to Grays Valley but were compelled to turn back for the snow On the 20th made another trial and succeeded and encamped at the Forks of `Gray's creek' here the ground was bare along the stream and some [on] the South sides of the hills but very deep on the high plains I killed two Bulls which came in good time after living upon Dried meat all winter Mch 19 we travelled up Grays creek about 10 Mls. There we found the snow very deep and hard enough to bear our horses in the morning. On the 22d we travelled on the snow up this stream about 5 Mls and encamped on a bare spot of ground where we staid three days Then started on the snow as usual and went about 8 Mls to the Valley about Grays Marsh where we found a bare spot about 40 rods square on the South side of a ridge and encamped The snow in the Valley was about 3 feet deep on a level Mch 28th We started on foot in the morning on the snow to hunt Buffaloe after going about 2 Mls we found 11 Bulls aproached and killed 10 of them on the spot we then butchered some of them and took out the tongues of the others buried the meat about 3 ft. deep in a snow drift laid some stones on the snow over it and burned gun powder upon them to keep away the wolves. We then took meat enough for our suppers and started for the Camp by this time the snow was thawed so much that we broke thro. nearly every step. Early next morning the snow being frozen we took two horses and went for our meat but when we reached the place where we had buried it we found the wolves had dug it up and taken the best of its notwithstanding our precautions. The Carcasses of the Bulls yet remained untouched by them and from these we loaded our horses and returned to camp.