Gunman who was killed by Yellowstone rangers had planned a July 4 mass shooting, park reveals The Associated PressGunman killed by Yellowstone rangers planned July 4 mass shooting, officials said FOX 4 News Dallas-Fort WorthYellowstone shooter approached building with 200 people inside while firing rifle, park says WyoFileYellowstone Gunman Was Firing Semiautomatic Weapon Toward Dining Area Cowboy State DailyUpdate on July 4 law enforcement involved shooting in Yellowstone National Park National Park Service