Lake Roosevelt National Recreation Area in Washington State has experienced several impressive waves caused by large landslides on the adjacent shoreline. The latest occurred last week, when a slide-triggered wave damaged shoreline facilities at a park campground.

The problems caused by such waves, which some have referred to as an "inland tsunami," was covered in the Traveler back in January, when a similar incident occurred. The use of that term is the subject of some debate, but no matter what you call those events, the results can certainly be impressive.

According to information from the park,

On Wednesday, August 25th, a large landslide occurred near the Blue Creek drainage on the Spokane Indian Reservation side of the Spokane Arm of the lake. Like the one that occurred on January 16th of this year, responding park staff found that a large section of hillside had broken free, creating a wave that was approximately 12 feet high by the time it hit Porcupine Campground on the southern shore less than a thousand yards across the lake.

Rangers had just cleared from a drowning in the Seven Bays area when emergency dispatch in both Stevens and Lincoln Counties alerted them to reports of numerous people in the water at Porcupine Bay as a result of the tsunami caused by the landslide.

Joining the park in responding to the incident were units from Lincoln and Stevens Counties, the Washington State Patrol, Medstar, Lincoln County EMS, and the Spokane Tribe. NPS rangers and maintenance staff responding to the incident stopped to perform a quick safety review before heading out on the water.

Damage to park facilities – including log booms, docks, and a swim platform – is estimated to be about $250,000. Although Porcupine Campground was closed to allow maintenance crews to perform emergency repairs and clean up, the campground reopened in time for visitor use by this past weekend.