According to bisonbasics.com, for the juciest and most flavorful ground bison is 80 to 90%lean (10 to 20% fat content).
2 lbs ground bison, 80 to 90% lean, medium texture preferred
1 - 1 1/4 tsp fine sea salt
1/4 - 1/2 tsp freshly ground black pepper
Break the ground bison up into small chunks by hand; spread the chunks evenly over a baking sheet. Sprinkle the ground meat with salt and pepper.
Shape the seasoned ground into 6 patties. Place the patties on a large plate, cover burgers loosely with some plastic wrap, and refrigerate for at least an hour to allow the patties to set.
Preheat the barbecue grill or prepare charcoal so that a medium-hot grill surface of 475 to 500F is maintained.
Brush some cooking oil on the top side of the burgers. Place the burgers over the coals on the pre-heated grill, top side down. The barbecue lid should remain closed during grilling. Grill burgers for 5 minutes. Open the barbecue lid, flip the burgers over and cook the opposite side for 4 minutes.
Move the burgers off the direct heat to the edge of the coals. Toast the buns on the grill at this time. Flip the seared burgers twice more over the next 4 to 5 minutes. Approximate total cooking time for burgers: 13 to 14 minutes.
After coming off the grill allow the burgers to rest for 5 minutes before serving.