SACRAMENTO, CALIFORNIA: Search and rescue teams are still trying to track down a missing 66-year-old traveling nurse from Michigan in rugged terrain near Sacramento, California, after she disappeared over a week ago while on a hike, authorities said.

According to the Calaveras County Sheriff’s Office, Ann Herford was last seen on the Arnold Rim Trail. Her colleagues reported her missing on November 14 after she failed to show up for work at Adventist Health in nearby Sonora, CBS affiliate KOVR-TV reported.

Ann Herford expressed interest in hiking the area

Herford expressed interest in hiking the area, per the sheriff’s office during breakfast with a friend on November 11. The Michigan woman was last seen the following day, per NBC affiliate KCRA-TV. However, a California Highway Patrol trooper found her car parked at the trailhead just three days later.

"It's not typical that someone will be staying the night out here," Sgt Chad Poortingha told KCRA, adding "Come nightfall and if there are still cars out here and if they are not staying the night, that's a cause for concern."

Search for Ann Herford has intensified over the last week

Over the last week, the search for Herford has intensified. On Tuesday, November 21, the Calaveras County Sheriff’s Office Search and Rescue team deployed 38 people to look for the woman, who family members say “lacked wilderness survival skills,” according to the sheriff’s office. Searchers on the ground are using canines while unmanned aerial systems have also been utilized in the effort to find the missing nurse.

What did Ann Herford's colleague say?

Anna Wettengel is Herford's colleague and said she's been keeping in contact with Herford's family in Michigan and added that everyone is anxious for any kind of update. She said they called her cell phone and it went straight to voicemail.

"Our hearts went into our gut and we were starting to get really scared," Wettengel told KOVR about first learning of Herford’s disappearance, adding "I mean, knowing that she's not from here, she's visiting, we didn't know that she didn't know the area."

She continued, “We're trying to still remain positive and we're just praying and hoping that she is okay and safe, and then she'll be able to come home.”

Sheriff’s officials ask the public to report any possible sightings of Herford or, if anyone has any information about her whereabouts, to contact the Calaveras County Sheriff’s Office at 209-754-6500.