A 3D terrain map of the Sangre de Cristo mountains above Santa Fe, NM. Drag to pan, scroll to zoom, right-drag (or Ctrl-drag) to tilt.
The ground elevation under the pointer shows bottom-right. The blue dots are water droplets on a fixed grid. Press Start and each walks downhill; ones that reach a pit or the edge darken, ones still moving when the run ends stay bright — give them a longer run.
Shift-drag a rectangle (the dashed box) to move the droplet grid to a new patch of terrain — pan anywhere first, even another state.
See README.md for how it works and where the elevation data comes from.