Friends say they're heartbroken and details remain sketchy following the death last week of a 37-year-old woman in the Ventana Wilderness area of Los Padres National Forest, near Big Sur.

Joanna Ruth Shields of Carlsbad was found dead near Sykes Hot Springs on April 9, and marks seen on her body suggest that foul play may have been involved. The death has officially been deemed "suspicious" by the Monterey County Sheriff's Office, but the official cause and manner of death have not been released, pending toxicology results.

As KSBW reports, Shields's body was found in a remote area by a group of hikers on Thursday morning. They were reportedly returning from a two-night hike into the backcountry, and Shields may have been on a similar backpacking trip.

One of those hikers, Gabe Holmes, told the station, "I didn’t see any blood. She was pale. She had markings around her neck. I don’t want to say, you know, choking marks, but when the firefighter lifted the jacket, he confirmed that she had a big gash on her head."

While no suspect or person of interest has been identified or arrested in the case, the group of hikers say they encountered a man in the area who claimed to be the dead woman's friend, and who appeared "cold and shaking."

According to hiker John Heerema, the man appeared "scared, nervous, like shocked, his face just, like, numb and dull."

Heerema's brother, Luke Heerema, explained to KSBW, "On one hand, we didn’t know if he was just having the worst day of his life or, on the other, like he had just killed someone, so I just went in with, like, all right, just be ultra-cautious, slow things down and make sure everyone’s safe."

Luke Heerema further relayed what the man reportedly told the group about how Shields died. "She went to the bathroom. She was cleaning herself off in the river around 10:30 am, and he went looking for her and then just saw her face down in the water, naked."

A GoFundMe campaign posted by Shields's friend Jessica Fessler describes what happened as a "backpacking accident" that has left her family and friends "heartbroken."

"Joanna moved through this world with brightness and spontaneity — in love with nature, her family, her friends, and her constant journey of self development," Fessler writes. "There was something so free about her… like she belonged to the wind and the sunshine."

Anyone with information that may be related to the investigation into Shields's death is asked to contact Monterey County Sheriff's Detective Geng at 831-755-3700.