Good British fur trading company kept meticulous records from the fur trading posts in Canada. The various forts, aka posts, had quotas for producing such foods as pemmican
which was to supply the actively travelling fur trading employees. For Rocky Mountain House, the Hudson's Bay Company records show that the annual quota expected for pemmican
was 44,000 lbs, done up in either 90 lb bison hide bags or 60lb bison hide bags for the really good stuff. (Jeez! You ever made real bison pemmican and tried to eat it? I have.)
That 44,000lbs quota was prepared in just 9 days. Dried meat. What? 10-15% of wet weight at most? So you gotta kill enough bison to see maybe 300,000lbs wet meat?
Then you have to render some 15,000lbs bison fat? The nuts and berries thing is a myth.
Horses could never help to match the bulk slaughter with a buffalo jump.
Now if you want to dispatch as many bison as possible with a rifle, you sure as hell don't want to be chasing them into a stampede on some silly horse.
They will be scattered all over the plains, rotting in the sun.
Instead, you lay back with a Sharps and kill everything out to 300 - 400 yards. Bison having "dirt-naps" and their pals don't get too upset, they all just standing around
which is freakin' exactly what a sharp shooting bison killer needs.
I still have family homestead photographs from a city originally named "Pile o' Bones." Now, the city is . . .. . . . . .. ??