STANLEY, Idaho (KIFI/KIDK)-Idaho Geological Society geologists believe the 6.5 Magnitude earthquake that struck central Idaho on March 31, 2020 may have had some significant impact at Stanley Lake.
After reviewing photos and satellite imagery of the inlet, the geologist said it appears a former boat launch, beach, and popular fishing area was flooded with deep water.
“The most probable cause for the “disappearing” of the inlet delta is a combination of liquefaction and compaction of saturated sediments and some possible sliding and lateral spreading on the delta toward the deeper part of the lake as a result of the March 31 earthquake or the associated aftershocks,” said Claudio Berti, Director and State Geologist, Idaho Geological Survey.
A newly constructed boat ramp replaced the inlet delta for boats in 2019. Aging campground infrastructure was replaced with a new Stanley Lake Campground on the east side of the lake. The inlet beach was still accessible through a trail and boardwalk.
“The loss of the inlet beach for fishing and recreation is unfortunate because that area was so popular with visitors at the lake, fortunately, the new boat ramp and campground construction were completed before this event, ensuring access for boaters and campers going forward,” said Brian Anderson, Deputy Area Ranger for the Sawtooth National Recreation Area.
Berti hopes to visit the actual site to collect data in the near future. He hopes that will help geologists describe the event and the overall geological characterization of the earthquake and its aftershocks.