American bison enter their mating season that stretches from June through late September, and peaks in July and August. With peak mating season now underway, the American bison's annual rut has already made headlines after a 2,000-pound bull charged 65-year-old Carl McDaniel, launching him nearly 8 feet into the air at Yellowstone National Park. The rut may be brief, but bull bison certainly make the most of it. Singing for a flingIn the competition to win over a mate, bull bison pull out all the stops. During mating season, bison bulls across Yellowstone National Park, South Dakota, Utah and other protected federal lands fill the prairie with deep, booming bellows.