The Rocky Mountains (or Rockies) form the largest mountain system in North America, stretching roughly 3,000 miles from northern British Columbia down to New Mexico. They were created between 55 and 80 million years ago during the Laramide orogeny, when shallow plate subduction pushed up a broad belt of peaks that were later sculpted by glaciers. The range boasts the continent's highest central peaks, including Mount Elbert in Colorado (14,440 ft) and Mount Robson in Canada (12,972 ft), with Colorado holding the highest average elevation. After the last ice age, humans settled the region, and later European explorers like Sir Alexander Mackenzie and the Lewis and Clark Expedition opened it up for resource extraction, particularly minerals and fur. The name derives from the Plains Cree word asinîwaciy (meaning "rocky mountain"), and today the range is a major tourist destination, protected by public parks and popular for activities like hiking, skiing, and mountaineering.