Yellowstone is the world's first national park, established in 1872. Check out this video from Yellowstone’s own park rangers Evan and Vivian, for their top tips on a successful visit. @NatlParkService @YellowstoneNPS https://t.co/8sWlBnOay7 https://video.twimg.com/amplify_video/1785933066520707073/vid/avc1/1280x720/-jaFTogyJ0ug3ECX.mp4?tag=14