How Coins Changed the Colors of Yellowstone's Hot Springs

One might mistakenly think that the vibrant colors of Yellowstone's hot springs have always been this way. However, a recent comprehensive study suggests that the 'lucky' coins thrown by millions of visiting tourists over the years are responsible for this sudden change in hue.

From 1940 to 2015, Yellowstone National Park welcomed over two million visitors annually. Many of these visitors would throw various metal coins into the hot springs, believing that doing so would bring them luck.

So how does such widespread vandalism cause such a sudden change? Millions of coins resting for years at the bottom of the natural pool blocked the underwater vents. Coupled with the accumulation of debris and natural waste, the pool's surfaces were forced to change their color.

Interestingly, due to its sudden change, the spring has been nicknamed "fading glory."