US Department of the Interior @Interior
The Tetons are one of the youngest mountain ranges in North America. They have been uplifting for less than 10 million years, making them "adolescent" mountains, compared to the Rockies (50-80 million years old) or the Appalachians (300+ million years old). Photo: @GrandTetonNPS https://t.co/ISlpZubxqn — PolitiTweet.org