&gt;&gt;  Hydrogeologists use a variety of dyes or other water additives that are better suited for this, and it doesn&#x27;t seem to have worked yet.<p>The one thing the article failed to mentioned is the possibility they have no idea where to look for the dye to be coming out. It&#x27;s easy to do this on an island (such as the famous Oak Island), not so easy at Kettle Falls where this waterfall is quite a ways inland and the only logical outlet would either be the Brule River, or a deep cavern that leads to the coastline of Lake Superior.<p>Add in the fact in some areas the lake can be as deep as 1,300 feet, and you&#x27;ve got one hell of a hard time trying to find out where the water goes.