The geography of waterfalls is not random.
Their distribution is determined by many factors which include: precipitation levels, topography,
bedrock type, and geologic structures. When you click an icon on the map above you will learn how many waterfalls are listed on United States Geological Survey 7.5 minute maps for that state (or maps of other scales if 7.5 maps were not published for the entire state). The information box that appears after clicking the icon will contain a link to a detailed map for that state along with a list of all waterfalls included on the map.
Big thanks to Google for letting us use their maps to make a fun page like this!