Photo by Chris Bernstein

My husband, Chris, and I were hiking in the Porcelain Basin at Yellowstone National Park, following a boardwalk trail over crusty, fragile-looking ground. Signs reading “Warning: scalding water” were everywhere, ordering you to resist the temptation to dip a finger into the colorful streams within arm’s reach. The air smelled of sulfur. Around nearly every corner was a bubbling pool, much like a jacuzzi set on low, but vivid blue or green in color. All of a sudden, “WHOOSH!” — a column of water shot up ten feet from the earth’s surface, maybe twenty feet away from us. Gaping, we tried to appear casual. Five minutes later, “WHOOSH!” — it happened again. Such is the unpredictable nature of Yellowstone National Park, where the earth is in constant turmoil.

Yellowstone, America’s first National Park, is best known for Old Faithful, the giant geyser that erupts in a towering stream every ninety minutes or so. But Old Faithful is only one of many geysers in the park, one among hundreds of hydrothermal attractions.

Visitors to Yellowstone are likely to see the great herds of buffalo and elk that roam the park, which are often visible at the sides of, or even the middle of, the road. It’s strange enough to witness a family of buffalo trotting alongside your car as you cruise through golden meadows and porcupine-like forests still recovering from the ’88 fires. But when, beyond the buffalo, you observe a cloud of steam pouring out of the ground for no apparent reason, the setting begins to feel surreal. Can you imagine what the early explorers must have thought?

Chris and I arrived in Yellowstone on Day 2 of a twelve-day road trip through Montana, Idaho, Wyoming and South Dakota. Following the Yellowstone River down Route 89 from Livingston, we passed through mustard colored hills dotted with pine and aspen. Grazing horses and giant cylindrical hay bales appeared at regular intervals. The mountains at either side were still enshrouded in mist as we entered Gallatin National Forest, the northern gateway to the park. But by the time we pulled into Fort Yellowstone, the sun was shining, as it does nearly every day of the year in the Rockies. It was a perfect day for touring.

. . . And there was so much to see. From a distance, Mammoth Hot Springs looked like vanilla ice cream melting down the side of a tall hill. The Norris and Old Faithful geyser basins appeared stark from afar, but up close they revealed a diverse palette of color. The Grand Canyon of the Yellowstone offered one scenic vista after another, from deep river gorges to huge waterfalls, to a stunning variety of rock and sedimentary deposits. Plus there were lakes, meadows, and mountains — and lots and lots of wildlife. Elk and buffalo for sure, but also moose, antelope, wolves and even bear (though luckily, we didn’t encounter any up close). And on top of all of that, to remind you that Yellowstone is unlike any other National Park in the US, random clouds of steam.

The steam is easy to explain. Yellowstone sits right on top of a geothermal hot spot. In fact, a large portion of the park is located within a caldera, the term geologists use to describe a basin formed by the collapse of a volcano. Two million, 1.2 million, and 600,000 years ago, powerful volcanic eruptions rocked northwestern Wyoming. Deposits from those eruptions have been found as far away as Iowa, Texas, and northern Mexico.

The same heat that caused the volcanos to erupt is what powers today’s geysers, steam vents, hot springs and mud pots. In the past eighty years, the center of the caldera has risen 86 centimeters. Scientists think this is due to changing levels of magma at a shallow depth beneath the earth’s surface. They say that the ground beneath Yellowstone is “geologically restless.” They also say that such activity is due to hydrothermal pressure changes and does “not necessarily” portent another eruption. Not necessarily.

It makes you wonder — if there have been volcanic eruptions at Yellowstone every 600-1200 thousand years, then isn’t the area due for another one?

You have to set such musings aside while touring Yellowstone. Certainly, this can be hard to do when you find trails closed “due to excessive hydrothermal activity.” But if you’re concerned about perishing in a torrent of hot magma, then you won’t really be able to appreciate the scenery. If you’ve bothered to travel most of the way across the country to see Yellowstone’s unusual topography, then you might as well enjoy it.

by Kezia Bacon-Bernstein, Correspondent
October 2004

Kezia Bacon-Bernstein’s articles appear courtesy of the North and South Rivers Watershed Association, a local non-profit organization devoted to the preservation, restoration, maintenance and conservation of the North and South Rivers and their watershed. For membership information and a copy of their latest newsletter, contact NSRWA at (781) 659-8168.