River Runner, a new map developed by data analyst Sam Learner, lets you trace the origins of water throughout the entire United States. Users can click on any location or enter any address and the map will show them where the water in that area is likely to flow to.

If, for instance, you click on a farm in southwestern Montana, you will learn that the fertilizer from that farm can travel more than 3,400 miles through streams and rivers in North Dakota, South Dakota, Iowa, and Missouri before it enters the Mississippi River and ends up in the Gulf of Mexico. This means that the fertilizer from southwestern Montana can eventually contribute to a giant algae-filled dead zone in the Gulf.

The information from the map may make people think twice about littering—through the map you can learn that plastic trash that ends up in a stream in West Virginia might make a journey that lands it in the same dead zone in the Gulf of Mexico.

Learner used data from the United States Geological Survey, and with the help from the USGS’s water data team, was able to map the flow path of water from every location in the US.

“What I really hope people take away from the tool, besides a fun visual experience,” Learner says, “is just how interconnected our waterways are, and the implications of that in terms of pollutants, agriculture, or water use.”