PSA: Do NOT lose the perfect bison pelt you get on the hunt with Charles.

[Demon of Razgriz]

Apparently, the bison seem to disappear off the face of the earth in that area after the hunt and the only ones left are in West Eliizabeth, which you aren't getting in because of the spawning Pinkertons that chase you down when you enter..... So, since I lost it, I apparently screwed myself out of being able to get the satchel upgrade for right now. :(

[samcharles77]

Bison should spawn in the Great Plains area. They are uncommon though so finding them may take multiple visits to the area.