Let's go to the past
Major Geological Events
Coral reefs develop, early continents collide with what is now North America forming mountains. Continental elevations were much lower and the ocean elevation was much higher. The sea rose dramatically as the glaciers from the late Ordovician period melted. Vascular plants started to plant and spread throughout the country. During this period the ocean covered most of the northern regions. Even though the ocean was higher than the land it was still very shallow compared to today it was only approx. 300 feet.