California teen vanishes during layover at Denver International Airport on way home from mental health center

 A teenager traveling back to her home in California reportedly never returned, after authorities said she was last seen during a stopover at Denver International Airport.

The National Center for Missing and Exploited Children said 15-year-old Harper Cadman disappeared Jan. 30 at Denver International Airport.

"Harper never boarded her flight back home and is believed to still be in the Denver or Boulder, Colorado area," an announcement from the National Center for Missing and Exploited Children said.

The organization said the teen was last seen when she landed in Denver at about 8:27 a.m. on Jan. 30 to fly back to California.

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In a Facebook post, Cadman's mother, Ari Petronelli, wrote a heartfelt message about her daughter's disappearance.

Petronelli wrote, "I'm sick to my stomach writing this and I never thought I'd have to post another missing flyer of my own child, but if this past year has taught me anything it's that life Doesn't make any sense." In a Facebook post.

Petronelli said her daughter was traveling from Montana back to her home in California, but never took a connecting flight on United Airlines.

She said her daughter was attending a mental health treatment center in Montana at the time of the incident.

“As many of you know, Harper was undergoing mental health treatment last year and while relocating back to California from Montana, she boarded an 8:30 a.m. United Airlines flight from Denver to Hawaii on 1/30. Disappeared at the base, Petronelli explained.

She has blue eyes and black dyed hair. Her nose is pierced, and she has tattoos on her waist and the middle finger of her left hand. She also has braces.

Prosecutors allege the father beat the daughter, then ate fast food and drugged her, causing her death in the back seat of their car.

Her mother said she was last seen wearing a white True Religion sweater, black leggings and black shoes. He had nothing else during the journey.

Authorities believe he is still in the Denver or Boulder area.

According to her family, she does not know anyone in Colorado.

If you have any information regarding Harper's disappearance, please contact NCMEC at 1-800-THE-LOST (1-800-843-5678) or the Denver Police Department at 1-720-913-2000.

The Denver Police Department did not immediately respond to Fox News Digital's request for comment.