Watersheds

This map shows how surface water flows in the United States. As you move the mouse over the map, the program highlights the upstream area in red, and the downstream area in blue. The coloring changes dynamically as you move the mouse. You can also zoom in or out on the map and pan around just like with other web based maps. If you click once on the map, the dynamic updating stops and the coloring "freezes" on the location where you click.

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