Follow a water drop’s path
River Runner is a website that lets you track a virtual raindrop's journey from any point on Earth to its final destination in the ocean. The 3D visualization is fluid, showing your water droplet flowing through rivers and streams, based on real geographic data. I spent too much time dropping rain on mountaintops and watching it wind through valleys all the way to the ocean. It's especially spectacular when starting from places like Yellowstone National Park, where you can watch the dramatic elevation changes unfold. It’s a perfect companion to John McPhee’s Basin and Range. — MF