In 2008, researchers dyed Wind Cave’s What the Hell Lake to map hidden water links; 1 month later, green dye reached 2 cave waters but left park wells clear

The most bizarre finds have led to some of the most peculiar site names in America's national parks. A little subterranean lake that emerged in the 1990s and blocked a channel that cavers had been using for years is located deep within Wind Cave in South Dakot