The primary mountain range in the United States is the Rocky Mountains. Stretching over 3,000 miles from Canada to New Mexico, the Rockies are known for their stunning peaks, diverse ecosystems, and recreational opportunities. They are significant for both their geological features and cultural importance, providing habitats for wildlife and opportunities for outdoor activities like hiking, skiing, and rock climbing. The Rocky Mountains also influence weather patterns and water resources across the western United States, highlighting their geographical and environmental significance.