The water that flows through Yellowstone National Park and the Greater Yellowstone Ecosystem (GYE) is a vital national resource. The headwaters of seven great rivers are located in the GYE, and flow from the Continental Divide through communities across the nation on their way to the Pacific Ocean, the Gulf of California, and the Gulf of Mexico. Precipitation (rain and snow) in the mountains and plateaus of the Northern Rockies flows through stream and river networks to provide essential moisture to much of the American West; and water resources provide recreational opportunities, plant and wildlife habitat, and scenic vistas.