National Monument • Nebraska
In the early 1900s, paleontologists unearthed the Age of Mammals when they found full skeletons of extinct Miocene mammals in the hills of Nebraska -- species previously only known through fragments. At the same time, an age of friendship began between rancher James Cook and Chief Red Cloud of the Lakota. These two unprecedented events are preserved and protected here... at Agate Fossil Beds.
42.42170419, -103.753886