Firehole Falls in Firehole Canyon - Yellowstone National Park, WY and MT. Firehole Falls in Firehole Canyon is a magnificent waterfall with a 40-foot drop into a rocky gulley that later turns into the Firehole Cascades.Firehole Falls - Yellowstone National Park, WY. The 40-foot Firehole Falls, on the Firehole River, rushes and tumbles through Firehole Canyon.waterfall Film Size 6X7cm