River Runner lets you follow the path of a drop of water anywhere in t

If a drop of rain falls in Chengdu, China, it will flow nearly 2,000 miles away to the East China Sea. In Cochabamba, Bolivia, rain flows through multiple rivers to the Amazon in Brazil, eventually reaching the Atlantic Ocean more than 3,000 miles away. Rain falling in Custer, South Dakota, travels 2,600-plus miles to the Gulf of Mexico.

The Euphrates River in Turkey [Image: River Runner]

A mesmerizing new map called River Runner lets you choose a spot anywhere in the world and take a bird’s-eye-view path through the local watershed, down streams and rivers that wind through mountains and fields. It’s a global version of a tool released last year that initially focused on American watersheds.

Data analyst Sam Learner built the project using data from the U.S. Geological Survey with help from the USGS’s water team and the Internet of Water, an organization that works on water data. (The back-end data needed to route the path of water globally didn’t exist in the right format, so the team had to build it.) Learner spent weeks tweaking the design to make navigation smoother; the tool is still in a beta version, with some names missing from streams and rivers.

The Canadian Rockies in British Columbia [Image: River Runner]

It’s fascinating to explore. “There’s something really interesting about ending up in little pockets of the country or world that you don’t know about at all, in interesting terrain,” Learner says. It’s also a clear illustration of how interconnected we are. He adds: “What we put in a river or stream ends up in someone else’s water.”