Yellowstone National Park is known for its geysers, hot springs and otherworldly landscapes. But beneath the spectacular views is a less visible problem: visitors regularly leave behind objects that can end up in the park’s fragile hydrothermal features.
The impact of this debris can go far beyond making the park look untidy. According to the National Park Service, Morning Glory Pool in the Upper Geyser Basin changed color during the 20th century, partly because visitors threw trash and other objects into it.
