The History of Yellowstone National Park

Pioneering mountain men traversed Yellowstone long before it became a national park—but found few who believed their tales of its wonders. Yellowstone, established in 1872, is the oldest national park in the world. It encompasses nearly 3,500 square miles (9,000 square kilometers) of high plateau country in the northern Rockies. Most of the park is located in the northwest corner of Wyoming, but parts of it extend into Montana and Idaho as well.

Wonders are everywhere in this unusual wilderness reserve. In addition to the park’s famous array of geysers and hot springs, there are rugged mountains, dense forests, deep, cold lakes, and rushing trout streams. Here too are found the spectacular Grand Canyon of the Yellowstone River, a cliff of solid black obsidian (volcanic glass) where Indians once quarried material for arrowheads, and even entire fossil forests. A loop road provides easy access to most of the park’s major features, and miles of trails thread through the backcountry wilderness.

But for most people Yellowstone is first and foremost a superb showcase of geothermal activity. With some 300 geysers and nearly 10,000 hot springs and steam vents, the park boasts the world’s largest, most varied collection of geothermal phenomena.

The boiling springs and spouting geysers are a legacy of the region’s volcanic past. The high, mountain-rimmed plateau was built up by a long succession of lava flows, the last of which occurred less than 100,000 years ago. Even now a reservoir of molten magma remains quite near the surface beneath the park. Water from rain and melting snow seeps into fissures, where it is heated by contact with hot rocks. Some then escapes to the surface through hissing steam vents, sputtering mud pots, and scalding hot springs. And some escapes in the intermittent fountains of geysers.

The best-known geyser in Yellowstone—perhaps in the world—is Old Faithful. Named for the regularity of its eruptions, it spouts on the average every 72 minutes, day after day, year in and year out. Its jet of steam and hot water, which lasts for two to five minutes, has been known to reach 184 feet (56 meters) but usually is about 130 feet (40 meters) high.

Riverside Geyser on the bank of the Firehole River is even more predictable, with 53%-hour intervals between eruptions. Although not as high as Old Faithful, it continues to play for 15 minutes, shooting a graceful plume of spray at an angle over the river.

Other geysers in the park’s various geyser basins show a wide range of eruptive activity. Some send up columns of water only three feet (one meter) or less in height and play almost continuously. Others produce much more substantial jets, but they erupt only at intervals of days, weeks, or even months. Steamboat Geyser, famous for producing the highest jets in the park, has been known to erupt to heights of 400 feet (120 meters). But in 1969 it mysteriously died. Renewed activity in recent years, however, suggests that it may be entering a new phase of spectacular eruptions.

Many other geysers vie for the visitor’s attention at Yellowstone. Castle Geyser erupts from an enormous fortresslike cone built from silica that was dissolved in the hot water. Grotto Geyser’s cone; penetrated by cavelike openings, resembles a huge abstract sculpture. Grand Geyser and Great Fountain Geyser regularly produce jets up to 200 feet (60 meters) high. The numerous hot springs, ringed by deposits of geyserite, are more notable for their colors than for any displays of activity. Among the most beautiful is Morning Glory Pool. The sky, reflected in its deep trumpet-shaped basin, produces a startlingly intense blue color.

The lovely hues in other hot springs are the products of various species of algae and bacteria, each adapted to life in water of different temperatures. Grand Prismatic Spring is blue in the center, but algae growing around the edges produce an amazing array of warm tones of yellow, orange, golden brown, and green. And, for reasons that are immediately apparent, Hillside Springs were once known as Tomato Soup Springs.

But the most spectacular by far are Mammoth Hot Springs near the park’s northern border. A fantastic structure of stepped pools and terraces, the springs adorn the slope like a gigantic wedding cake. Here the hot water spilling from the pools is saturated with dissolved limestone; it is estimated that 2 tons (1.8 metric tons) are brought to the surface each day. Precipitated from the water, the limestone deposits cause the terraces to change slowly but constantly both in size and shape. As in the other springs, heat-tolerant algae streak the terraces with ribbons of delicate colors.

Although less well known than its hot springs and geysers, Yellowstone’s fossil forests are equally impressive. Spread over an area of some 40 square miles (100 square kilometers), they are the most extensive petrified forests existing in the world. The trees, moreover, were buried alive in outpourings of volcanic debris; in contrast to most other petrified forests, where the logs are strewn in a helter-skelter fashion across the ground, the fossilized tree trunks at Yellowstone remained in upright positions.

Nor is there just one petrified forest at Yellowstone. As one forest was buried, a new forest took root above it in the volcanic debris, only to be buried itself by renewed eruptions. More than 12 separate layers of petrified forests have been unearthed in the park. With details of foliage, twigs, and cones faithfully preserved as fossils, more than 100 different species of trees have been identified, ranging from relatives of modern redwoods to various types of maples, chestnuts, oaks, and figs.

No visit to Yellowstone is complete without a pause to admire the park’s own Grand Canyon. Flowing north from Yellowstone Lake, the largest high-mountain lake in North America, the Yellowstone River plunges into an awesome abyss by way of two mighty waterfalls. The first, the Upper Falls, has a drop of 109 feet (33 meters); the Lower Falls are an imposing 308 feet (94 meters) high.

Downstream the bright green water of the Yellowstone River rushes through a canyon 24 miles (39 kilometers) long. Averaging 1,000 feet (300 meters) in width, it is up to 1,200 feet (365 meters) deep. From overlooks on the canyon rim such as Artist Point and Inspiration Point, visitors can readily grasp the size and beauty of this spectacular canyon in this varied and magnificent national park. Anna lives and works in Prague.