My father worked for Mountain Bell and was sent to Hebgen Lake after the earthquake to assess damage done to Mountain Bell equipment and transmission lines. I found some of the pictures that he took. I'm sure there are more but I still haven't found them.
The 1959 Yellowstone earthquake also known as the Hebgen Lake earthquake was a powerful earthquake that occurred on August 17, 1959 at 11:37 pm (MST) in southwestern Montana. The earthquake was registered at magnitude 7.3 – 7.5 on the Richter scale. The U.S. Weather Bureau reported that the quake lasted 30-40 seconds. During the earthquake the surrounding landscape dropped as much as 20 feet (6 m) and shockwaves caused numerous seiches to surge across Hebgen Lake for 12 hours. Water pushed by the seiches poured over the dam which did not collapse. Several aftershocks ranging from 5.8 to 6.3 were reported after the quake.
Scanned pictures can be seen here: Hebgen Lake Earthquake