Check out the tool! 

A new online tool released by the Department of the Interior this week allows users to select any major stream and trace it up to its sources or down to its watershed.

The above map, exported from the tool, highlights all the major tributaries that feed into the Mississippi River, illustrating the river’s huge catchment area of approximately 1.15 million square miles, or 37 percent of the land area of the continental U.S.

Use the tool to see where the streams around you are getting their water (and pollution).

Read more: http://www.slate.com/articles/news_and_politics/map_of_the_week/2013/07/chart_tributaries_of_the_mississippi_river.html#ixzz2ZiQ9r0ZX

What's funny is that neither you nor me lives anywhere close to the Mississippi River.