The discovery was made around 6:20 p.m. above the Cobb Estate near Lake Avenue and Loma Alta Drive, about two miles from the Chaney Trail Road. Officials said the bones, later confirmed to be human, appeared to have been at the location for a while.
Cadaver dogs, homicide detectives, coroner's officials and a Special Operations Response Team responded to the scene Monday morning and found additional human remains, along with some clothing. The trails leading up to Echo Mountain were closed for the investigation.
Coroner's Assistant Chief Ed Winter said it's unclear if foul play is involved.
"We don't rule out anything at this time. We do get a lot of transients and hikers that do visit this area, and so at this time it'd be too quick to say whether or not there is foul play," Winter said.
Sheriff's deputies say there are no reports of missing people or hikers in the area but they plan on continuously checking their databases for updates.
Homicide Bureau and coroner's office investigators were working to identify the person by researching missing person's reports and possibly dental records, LASD officials said.
Anyone with information about this incident is encouraged to contact the Los Angeles County Sheriff's Department's Homicide Bureau at (323) 890-5500. If you wish to remain anonymous, call (800) 222-TIPS.