Yellowstone, America’s First National Park

The scenery that early explorers, surveyors, artists, and photographers encountered at Mammoth Hot Springs was among the most striking in the park. Hot waters heavily charged with lime had built up tier upon tier of elaborately carved and fretted terraces made of a hard rock called travertine. The springs that created the terraces, like this terrace the explorers named “Pulpit,” were constantly moving and shifting—leaving old terraces dormant and forming new ones.

Norris Geyser Basin changed daily due to water fluctuations and seismic activity. New hot springs and geysers appeared, while others became dormant. Constant Geyser, on the left, was a relatively frequent performer, spraying twenty to thirty feet high in few-second bursts. Black Growler, in the background, was a steam vent—a cluster of hissing holes in a barren hillside that emitted a thick tower of steam, occasionally switching from one hole to another.

Lower Geyser Basin sat on unstable glacial gravel atop solid rock—causing effects like bubbling mud pools and unpredictable increases in water temperature. When it erupted, Fountain Geyser was one of the most impressive geysers in the park, reaching twenty to fifty feet in the air and lasting twenty-five minutes or more.

The so-called “Paint Pot” in Lower Geyser Basin was an oxide-colored pool of mud composed of hot clay minerals and fine particles of silica. It became famous for its blooping and spitting sounds. Bursting bubbles might unexpectedly lob high into the air.

The tallest predictable geyser in the park, Grand erupted from a large pool of powerful bursts every seven to fifteen hours. Average eruptions lasted nine to twelve minutes, in one to four bursts that sometimes reached 200 feet in the air. Grand Geyser was connected to other geysers in the so-called Grand Group, which also included adjacent Vent Geyser and Turban Geyser.

Old Faithful was the most famous and celebrated geyser in the park—and indeed the world. Members of the 1870 Washburn Expedition, who camped near this geyser, named it Old Faithful because they discovered that it erupted at frequent and regular intervals (averaging about every ninety minutes). Each eruption emitted 10,000 to 12,000 gallons of boiling water for a period of two to five minutes, with water reaching a height of 90 to 184 feet.

Yellowstone Lake—one of the coldest, largest, and highest lakes in North America—was a jaw-dropping discovery for early explorers. The shoreline covered 110 miles at an elevation of almost 8,000 feet above sea level. This photograph was taken from Stevenson Island, which later became a popular spot for fish fries during tourist excursions on the lake.

Fish Pot Hot Spring, also called “Fishing Cone,” is a shoreline geyser that protrudes from the bottom of Yellowstone Lake. Early tourists claimed that they could catch a trout from the lake, and without moving a step, cook the fish within a few minutes by dipping it into the boiling water inside the cone while the fish was still on its line. By the 1930s, this practice had been prohibited.

This petrified redwood tree is a remnant of the trees that were once part of a great primeval forest. Three petrified trees once stood on this site but two were carried off in pieces by souvenir hunters. This remnant was surrounded by a protective iron fence in 1947.