Missing family of three and their dog found dead on hiking trail in remote area of Sierra National Forest

Investigators using hazmat suits as unexplained deaths follow missing persons report

Ellen Chung and Jonathan Gerrish with their one-year-old Muji. (KSEE/KGPE by Rosanna Heaslett)

A family of three and their dog have been found dead in a remote area of the Sierra National Forest, after they were reported missing, authorities in California have said.

Identified as John Gerrish, Ellen Chung, and one-year-old Muji, the family were found on Tuesday evening near an area known as Devil's Gulch, in the Southfork of the Merced River, the Mariposa County Sheriff's Office said.

Search teams had located the vehicle belonging to the family, who were reported missing by a relative on Monday, not far from Devil’s Gulch.

It was not clear what caused the deaths of the family or the dog, and investigators were treating the incident as a “hazmat and coroner investigation”.

A spokeswoman for the sheriff’s office, Kristie Mitchell, told CBS News: "It could be a carbon monoxide situation. That's one of the reasons why we're treating it as a hazmat situation”.

The area where the family were found, Ms Mitchell said, has no cellphone service. It was close to the Hite Cove trail, which is known for its wildflowers.

“This is never the outcome we want or the news we want to deliver, my heart breaks for their family,” added Sheriff Jeremy Brierse in a statement.

“Our Sheriff’s Chaplains and staff are working with their family and will continue to support them during this heartbreaking time.”

A friend of the family told Fox26 News that they were last heard from on Sunday, when they shared a picture of backpack to their social media accounts.

It comes after miners in Colorado died after they were exposed to fatal levels of carbon monoxide following an explosion in 2019, in an event that sickened 19 others. Officials in Mariposa County have not ruled out a similar event in the deaths.