By Mireya Villarreal CBS News December 9, 2018, 6:40 PM Search intensifies for missing Colorado mother Kelsey Berreth

For more than two weeks, no one has seen or heard from 29-year-old Kelsey Berreth. One of the last places the young mother was seen was on Thanksgiving Day at a Safeway in Woodland Park, Colorado, wearing a white shirt, gray sweater and blue pants. She was reported missing Dec. 2.

"If she's out there and doesn't want to be contacted, just let us know that she's safe and we'll let her family know," said Cmdr. Chris Adams of the Woodland Park Police Department.

A few days after Thanksgiving, her cellphone pinged nearly 800 miles away outside Gooding, Idaho, not far from where she has family, Adams said.

Kelsey Berreth

CBS Denver

In Washington state, where some of Berreth's family lives, a vigil was held by her brother-in-law, Brandon Kindle. "If they see her anywhere, please, please, please, please say something," Kindle said.

Thousands are following a Facebook page that regularly posts pictures and updates on her case.

Her brother traveled to Colorado to help find her. He shared a Facebook post that read: "After arriving at Kelsey's house last night and combing through her things, we know 1 thing is certain. Kelsey did not pack to go anywhere. All luggage is here. Her purse is all that seems to have gone."

Berreth's cars are still in Colorado. Police told CBS News they have searched Berreth's home for clues and are working closely with the family to learn more about her, including her life on social media and anyone she was in contact with.