The Lewis Range is a mountain range located in the Rocky Mountains of northern Montana, United States and extreme southern Alberta, Canada.

It was formed as a result of the Lewis Overthrust, a geologic thrust fault involving the overlying of younger Cretaceous rocks by older Proterozoic rocks.

The range is located within Waterton Lakes National Park in Alberta, Canada and Glacier National Park and the Bob Marshall Wilderness Complex in Montana, United States.

The Chinese Wall in the Bob Marshall Wilderness is a 1,000 ft (300 m) high feature that runs for 40 miles (64 km).

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.