American Bison: Lamar Valley, Yellowstone National Park, September 2024 — Bison are mostly placid animals, even the bulls, but during rutting season you can catch some action. Rut was mostly past in the Lamar Valley when we got there, but this bull had apparently not gotten the memo. He was actively defending what appeared to be a still receptive cow. A bull from an adjacent group was showing interest. He was having none of that! I would not want to see this fellow coming for me. Sony a6700 with Tamron 50-400 Di iii zoom at 600mm equivalent. Program mode with my bird and wildlife modifications. Processed in Photomator.