Bear fat can be acquired from almost any Native Community, some buy off the net.......one could contact their local Hunters Association.
http://www.bottlebooks.com/bearoilstory/bearsoil.htm
What I do is to trim the fat of all meat. Then, using a cast iron pot or stainless, (do NOT use aluminum, as it will taint anything whether you're going to eat what's cooked or not), turn the fat into "oil" by slowly cooking it.
You want to run your exhaust fan and do NOT cover the pot, as you don't want any moisture in the "oil."
Once the fat is melted, I strain it through multi-layers of cheesecloth into clean coffee cans, etc. Once cooled, you can preserve it by freezing it. To make a good cold weather patch lube, melt the "oil" and then melt 20% beeswax into it. Stir well, and poor into a clean jar, tin, etc.
What I've found is that the beeswax preserves the bear oil, i.e., it won't turn rancid.