Constructive Forces of Mountain Building Activity Source: Esri. Adapted with permission. Materials Computer with internet access Procedure 1. Start the map at http://www.arcgis.com/home/webmap/viewer.html?useExisting=1. 2. Explore: Does North or South America have the biggest mountain range? Click Modify Map, and then click the Contents button. Click the Rocky Mountains bookmark, then click the Andes Mountains bookmark for closer examination. Compare and contrast the Andes and Rockies. Measure the Rocky Mountains and the Andes Mountains. [Read More]