Madison River Canyon Earthquake Area

A visitor center with interpretive displays sits at the site of a massive 1959 earthquake and landslide.

At 11:37pm. on Monday, August 17, 1959, one of the most severe earthquakes recorded in North America shook the area around West Yellowstone.

The quake measured 7.5 on the Richter scale and sent gigantic tidal waves surging down the seven-mile length of Hebgen Lake, throwing an enormous quantity of water over the top of Hebgen Dam. This water, described as a wall 20 feet high, swept down the narrow canyon. Fortunately the dam held against the tidal waves, although it cracked in at least four places. At about the same time, half of a 7,600-foot-high mountain came crashing down into the valley. The slide dammed the Madison River and forced the surging water back up the canyon.

It took eight seconds for 80 million tons of rock to fall to the valley floor 1,200 feet below. When it reached that point it was estimated to be traveling at 175 miles per hour. Four-thousand-pound cars were tossed 40 feet and smashed against trees by the force of the near-hurricane velocity wind created by the falling mountain.

Another shock occurred every 15 to 20 minutes during that night and the following morning. Some 250 people were trapped in the Madison Canyon when big sections of the road fell into Hebgen Lake.

The next morning eight smokejumpers were dropped with food and first aid equipment. They also helped prepare a landing spot for an evacuation helicopter.

When the mountain fell, it covered the unimproved section of Rock Creek Campground, burying several people. It was not feasible to move 80 million tons of dirt and rock, so much research was done to determine how many people were missing. It is estimated that 19 are buried beneath the rubble.

Two people, camped at the Cliff Lake Campground, were killed when two boulders (each weighing eight tons) came crashing down a mountain and landed on top of them as they lay sleeping.

The final death toll for the earthquake stands at 28.

In nearby Yellowstone National Park, 18,000 people were overnighting and most were on the edge of panic. At Old Faithful Inn, the fireplace and chimney crashed through the dining room floor, activating the sprinkler system. Water damage was substantial.

The only injury in Yellowstone was a woman who sprained her ankle jumping out of bed.

At Canyon Village, a guest left a note on his pillow the following morning for the maid, saying, "An awfully rough bear stayed under my cabin last night. Had an awfully hard time sleeping. Better tell the night man to do something about it."

To preserve the effects of the earthquake on the geology and man-made structures, the Forest Service set aside 37,800 acres of the Gallatin National Forest as the Madison River Canyon Earthquake Area.

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General Information

The Visitor Center, built on top of the slide, is open daily, 8:30am to 6:00pm, May 24 to September 24. On display are photos of the area just after the earthquake and a seismograph. There is also a regularly scheduled video about the earthquake.

Services for travelers are available in nearby West Yellowstone.

Admission: $3/car, $15/tour bus, $1/motorcycle and bicycle.

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For more information:

Madison River Canyon Earthquake Area
Hebgen Lake District Ranger
PO Box 520
West Yellowstone, MT 59758
406-823-6961

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