Bear fat has been used since the first nations people. It's probably the 3rd most important animal behind beaver and buffalo to western expansion. Because bears hibernate in dormancy they pack on fat, and that fat is a unique fat. Other North American animals hibernate like squirrels and prairie dogs but none that are big enough to render fat from. Likewise other North American big game like whitetail, mule deer, and elk who don't hibernate don't offer much in the way of renderable fat.
Bear fat when ground down and slow cooked with a bit of water and strained through a cheesecloth makes a clean lard that works great for both frying and baking. It's how Native Americans, early settlers, and pioneers fried the lean rabbits, squirrels, and deer meat they were shooting along the way. They also used it for conditioning bow strings, weatherproofing clothing, seasoning knives and firearms, protecting skin and chapped lips, soothing insect bites and rashes, making soap, and to burn lanterns. Lewis and Clark reported using gallons of bear fat to condition their equipment. It's kind of like having WD40, Crisco, and Vaseline all bottled up in one little jar.
I've never killed a bear nor rendered bear fat, but I've been around it. I worked for a while as guide/outfitter and you'd get hunters that would bring it to camp for cooking or trading. I traded a guy a youth recurve bow for a big mason jar several year back and cooked with it for months. It's the same idea as frying with bacon fat except it's cleaner and has a longer shelf life.