Learn about the geological history of North America in this video from NOVA Digital. Google Earth flyovers and visualizations from NOVA's Making North America illustrate how particular locations, landscapes, and life forms have changed through time. For example, the bedrock that is the foundation of New York City was formed from the erosion of mountains that were built from the seafloor 450 million years ago; the sandstone cliffs of Zion National Park were once desert sand dunes; and 130 million years ago, the dry plains of Kansas were the site of a vast ocean. The plate tectonics and surface processes that shape Earth are ongoing, and North America continues to change. This video contains segments from NOVA: Making North America. This resource is part of the NOVA: Making North America Collection.