The mountain system that runs along the western coast of South America is called the Andes Mountains. Stretching over 7,000 kilometers, the Andes are the longest continental mountain range in the world. They span through several countries, including Argentina, Chile, Peru, and Colombia. The Andes play a critical role in the continent's ecology and climate, impacting weather patterns and biodiversity. They also hold significant cultural importance for many Indigenous groups and are known for their rich mineral resources.