Possible contributing factors explored:

The Sheriff’s Office recently contacted Naval Air Station Fallon and Hawthorne Army Depot in our neighboring state of Nevada. Both installations confirmed that they conduct daily ordinance explosions for various reasons. For example, Naval Air Station Fallon deploys aerial bombs and live ordinance detonations as part of their training regimen. High speed fighter/bomber aircraft that are assigned to the Station can break the sound barrier during flight. Flights are often higher in altitude than the elevation of the Sierra Nevada Mountains that separate us. They said they conduct these kinds of operations at various hours throughout the week.

Hawthorne Army Depot said it conducts ordinance disposal operations Monday through Friday between the hours of 11:00am and 2:00pm. These particular hours of operation are consistent with most of the explosions reportedly heard in the Swansboro area of the county. The Depot is housed on about 147,236 acres just outside of Hawthorne Nevada with manufacturing, storage, and demilitarization of conventional (non-nuclear) ordinance capabilities.

All of these explosions and operations coupled with atmospheric conditions, geography, altitude, and distances all play a factor in the way sound travels. Considering that the Naval Air Station in Fallon Nevada is about 160 miles away from the Mosquito / Swansboro area, while the Hawthorne Army Depot is located approximately 200 miles away, they are most likely the source of some noise. Military personnel from both locations confirmed it is possible for the sound created by these explosions and breaking the sound barrier at altitude can reach areas within El Dorado County. However, they remain somewhat skeptical that these detonations could be heard from this distance on a daily basis as atmospheric conditions change.

According to the Sheriff’s Office Records Division, no local explosive permits have been issued that could be the source or cause of this noise.

On Monday, June 8th, the El Dorado County Sheriff’s Office Search and Rescue Team based in South Lake Tahoe, responded to two separate Search and Rescue incidents. Both incidents involved injuries to backcountry hikers.

The first Search and Rescue began at 12:43 PM, when an adult male hiker fell at Cascade Falls causing traumatic injuries. Due to the hiker’s injuries a hoist capable helicopter was requested and provided by the California Highway Patrol. With the assistance of ground personnel from Lake Valley Fire Department, USFS and Cal Fire, rescuers were able to provide care and get the hiker hoisted out and transported to a medical air ambulance helicopter provided by CALSTAR. The victim was then transported to Renown Medical Center for further care.

The second Search and Rescue occurred at approximately 4:00 PM, when a teenage male hiker fell almost 40 feet down a cliff band at Pyramid Creek (Horsetail Falls) Trail, approximately 1 to 2 miles up the trail. The victim suffered traumatic injuries requiring advanced care. With the assistance of ground teams from Lake Valley Fire Department, Cal Fire and California Highway Patrol Air Operations, the victim was hoisted out by helicopter and transferred over to a medical air ambulance helicopter provided by CALSTAR. The victim was then transferred to Sutter Roseville Hospital for further care.

The El Dorado County Sheriff’s Office wants to remind individuals who recreate in the backcountry to be prepared for emergencies. This would include having proper equipment, such as clothing, first aid supplies, maps, food, water and possibly a personal locator beacon. In addition, make sure to advise family and friends of your hiking plans and completing a wilderness permit if necessary.

The El Dorado County Sheriff’s Office is happy to report that June Smith has been located safe and unharmed. Smith was previously reported as an at-risk missing elderly adult and a Silver Alert had been generated. We would like to thank June’s family, the public, the media and allied agencies for all of their help