This is a calorie-rich food used by indigenous peoples of the past which we should all know about for survival. Just one pound was an estimated 3,500 calories. It was dried and lasted for months. Do a quick search and you will find many recipes. It is a mixture of tallow, dried bison, and dried berries. From what I read, you can live off of it indefinitely.
European settlers in the Great Plains are estimated to have reduced the American bison population from 30 million to just 325 by the 1880s. I can imagine this made it difficult for Native Americans to survive.