Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Split Mountain (8,792 feet (2,680 m)) is located in the Lewis Range, Glacier National Park in the U.S. state of Montana. The Lewis Range is a mountain range located in the Rocky Mountains of northern Montana, U.S. and extreme southern Alberta, Canada. Formed by the Lewis Overthrust beginning 170 million years ago, an enormous slab of Precambrian rocks 3 miles (4.8 km) thick, 50 miles (80 km) wide and 160 miles (260 km) long faulted and slid over newer rocks of the Cretaceous period. In this relatively rare occurrence, older rocks are now positioned above newer ones.