After the cutscene, follow Javier up the mountain and carefully traverse the treacherous terrain. Continue until you find John’s dead horse near the peak.
Follow Javier until you reach a path that’s too narrow for horses. Before going ahead, swap your sidearm to your sawed-off shotgun from your saddle. Follow Javier and continue forth until you finally find John by a easily-missable ledge.
After the cutscene, you’ll find another way back to your horses. However, there’s a wolf pack waiting there as well. Head towards the wolf pack and call their attention while Javier head towards your horses. Your shotgun is powerful but it can only do two shots at a time so make sure to aim carefully before firing. After taking out all three wolves, rush back to your horses and ride downhill. Make sure to consume some provisions as needed.
While riding, you’ll encounter more wolves. Equip your shotgun and kill the wolves while riding. Don’t waste your bullets by shooting from a distance; instead engage them at close range for more accurate and devastating shots. After taking out all the wolves, just continue riding until you reach the camp. Mission complete.