Preheat a skillet over medium heat. Form the bison into patties, about ½ inch thick.
Season both sides of each patty with kosher salt and black pepper to taste. Add dried oregano and garlic powder. Grill for 3-4 minutes per side until done (internal temperature should reach at least 160°F).
Heat a nonstick skillet with olive oil cooking spray over medium heat. Cook the patties in batches, flipping once, for about 2-3 minutes per side until they develop grill marks and reach an internal temperature of at least 160°F. Serve on toasted buns or lettuce wraps with your choice of condiments.