This was fun to play with but I was surprised by the unevenness of the data.
I could pick random points in the US or Canadian Rockies, and this would have a path that starts out with some minor creek. But if I picked a point in some parts of the world (e.g. the Himalayas) there would be a chain of multiple "Unidentified River" entries, some of which seemed like they would be quite significant.