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Inquiry Question

Historical Context




Table of

Locating the Site

Map 1: In the flood's wake.
[Map 1] with link to higher quality map.
(National Park Service)


1) When the South Fork Dam (elevation 1,650 feet) was breached, the lake waters followed their natural course downhill along the river, growing stronger and more destructive as the flood waters picked up and carried along everything in their path. The first town struck was South Fork, two miles downstream. The flood claimed its first four victims and 20 to 30 homes were destroyed.

2) When the wave reached the two-mile long oxbow in the river it split. Part of the wave left the river channel here, crossed the oxbow, and hit the 75-foot-high stone viaduct. Because the water was choked with debris by this time, it was temporarily dammed at the arch. The greater part of the flood followed the oxbow, and crashed into the viaduct six to seven minutes later. For a brief moment, the wreckage at the viaduct created a second dam for Lake Conemaugh. When the viaduct collapsed, it did so with even greater violence than the South Fork Dam.

3) A mile below the viaduct the sawmill town of Mineral Point was struck by the renewed force of the wave. Thirty families lived on the village's main street, but when the flood had passed, only bare rock remained. Sixteen people died.

4) The wave headed toward East Conemaugh. A witness said the water by now was almost obscured by the debris, resembling "a huge hill rolling over and over,"tossing up logs high above its surface. Before the flood hit East Conemaugh, train engineer John Hess tried to warn the residents by tying his train whistle down and racing toward town ahead of the wave. His warning saved many, but 50 people died, including about 25 passengers on trains that had been stranded in the town by earlier flooding caused by the rain.

5) As the river straightened out between East Conemaugh and Woodvale, the flood gathered speed and power. Woodvale had no warning. Part of a mill was all that was left standing after the flood struck. Of 1,100 residents, 314 died. When the Gautier Wire Works were hit, boilers exploded creating what flood survivors in Johnstown called the black "death mist."

6) The flood hit Johnstown (elevation 1,174 feet) with full force, bearing the remains of the Conemaugh Valley. The time was 4:07 p.m., 57 minutes after the dam had broken. Again, the wave split, sparing some buildings in the center of town. Still in use is the stone bridge, where the mass of debris, animals, and humans piled up and caught fire, taking 80 lives. By now, the torrent had spent its force and the wave continued to break up and lose speed as it continued its downward course. It caused no more damage.

Questions for Map 1

1. Find Johnstown on a map of Pennsylvania and describe its location within the state.

2. Trace the path of the flood wave. How many towns were affected by the flood?

3. What happened at the oxbow? Why do you think this occurred?

4. What is the elevation change between the dam site and Johnstown? How would this have affected the flood wave?

* The map on this screen has a resolution of 72 dots per inch (dpi), and therefore will print poorly. You can obtain a high quality version of Map 1, but be aware that the file may take as much as 30 seconds to load with a 28.8K modem.



Comments or Questions

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