The mountain range that forms the natural border between the U.S. and Canada is the Rocky Mountains. Stretching over 3,000 miles from Canada to New Mexico, this range is known for its stunning landscapes, diverse wildlife, and recreational opportunities. The Rockies play a significant role in climate regulation and water supply for both countries, acting as a crucial watershed. They are also a popular destination for outdoor activities such as hiking, skiing, and camping, drawing millions of visitors each year.