A spate of reports on irresponsible meddling and mishaps in Yellowstone National Park this spring set the stage for my visit there last month. It’s easy to laugh when tourists face the consequences of their determination to get the perfect bison, bear or moose selfie. Less entertaining was the group who, having spotted a lone bison calf, decided that it looked cold and put it into the back of their SUV. The calf later had to be euthanized when its herd refused to accept it back. All this had me braced to witness misbehavior in the park, with humans proving a danger to themselves and the wild park inhabitants. Just prior to my visit, though, two more incidents highlighted the dangers of the park itself: in the hydrothermal areas, where geysers and hotsprings bubble up through the ground, a man and his son slipped and were burned, and in a separate incident, another man fell into a thermal pool and died.
My trip took place after the end of a department field trip to Wyoming, and as we got ready to split from the group to head to Yellowstone, everyone, from professors to grocery store cashiers to hotel clerks, repeated the headlines back to us and warned us to be careful, to not leave the trails. At the park, signs everywhere warned the same things: Do not leave the boardwalk. Bear selfies? Not ever. Do not approach within 100 yards of bears or wolves, 25 yards for other animals. Less than a week after a fatal accident, you might think these cautions would be in the front of everyone’s minds, but we still saw people stepping off the boardwalks onto steaming ground, posing for the perfect snapshot.
Yellowstone, the world’s first National Park, is also one of the National Park Service’s top destinations, with 4 million visitors a year. Most of its most famous features like Old Faithful and the Great Prismatic Spring are easily accessible to visitors driving through the park, usually with a parking lot and rest area immediately adjacent. The heavy traffic and ease of access create, it seems, the impression that Yellowstone is a tame park. The truth is, Yellowstone and most especially its hydrothermal areas are at once volatile, ephemeral, and fragile, as susceptible to being harmed as to doing harm.
This was pretty well demonstrated at the Grand Prismatic Spring, the famous rainbow-hued hotspring that steams in the Midway Geyser Basin. To approach the spring, you cross the Firehole River on a walking bridge and climb a ramp up the mounded calcite deposits to Excelsior Geyser. There was a stiff breeze blowing the hot steam into our faces as we approached, alternately obscuring and revealing the view ahead, and it only get stronger at the top of the spring. As a result, the rust-red surface was scattered with lost hats, so regularly distributed that they seemed like a modern art installation. Some were just beyond arms reach from the boardwalk, which must have tempted their owners to follow the example set in May by a group of Canadians, who walked out onto the surface of the spring to take pictures and have since been faced with criminal charges. The crowning touch was a single black umbrella, sharp and distinct at the bottom of the clear blue waters of Excelsior Geyser.
Park staff use long-handled tools to remove litter from the surface, but items lost to the depths of the thermal pools are difficult to retrieve, with sometimes long-reaching consequences. The brilliant colors of the Grand Prismatic spring are the result of bacteria which form microbial mats around the edge of the spring; their color is a reflection of the temperature gradient from the center to the edge of the pool. The microbial structures are easily damaged – both by tourists’ feet and changes to the ambient chemistry. The spring itself is 121 feet deep, making it unlikely that trash, lost hats, or crashed drones (as happened in 2014) will ever resurface, and though its rainbow colors haven’t been diminished yet, Yellowstone is well aware of how dramatically a spring can change under human influence. Morning Glory pool was named for its vivid blue, opening in the ground like the bell-shaped flower. Today, it is a murky green and yellow. Decades of trash and lucky coins tossed into the blue well blocked the vents providing heat to the system, lowering temperatures and preventing proper circulation.
Seeing Yellowstone, even for the day-and-a-half whirlwind tour that I had, was a wonderful experience, especially for an earth scientist. It was a rare chance to get up close (but not too close) and personal with a strikingly active geothermal system, in one of the country’s most stunning natural settings. The beauty of Yellowstone only makes the negative effects of human activity stand out all the more. This year is the centennial of the National Park Service, drawing additional focus to the issues facing the national parks in this century: how can we protect park ecosystems from irreversible damage while still encouraging the public to engage and explore America’s public lands? I’d start by leading with the following reminder, at least at Yellowstone: Hold onto your hats, and leave the animals and the hotsprings alone. It won’t end well for you or them.