(Photo : Marin County Sheriff's Office)
Mint Butterfield was located six days after they first went missing, the family announced

An heiress to a billion-dollar tech fortune went missing in Marin County, California, four days ago and is feared to be roaming the streets of Tenderloin, one of San Francisco's heaviest drug-infested neighborhoods. 

Mint Butterfield, 16, is the only child of two of the prominent Silicon Valley entrepreneur, Stewart Butterfield, who is the co-founder of the messaging app Slack, while her mother, Caterina Fake, founded the imaging service Flickr.

A missing poster put up all over the Bay Area states Mint was last seen on Sunday night at around 10 p.m. in Bolina, California, and was reported missing by her mother, according to the Daily Mail.

The 16-year-old, who has allegedly battled addiction issues in the past, attends a private boarding school in Napa Valley.

The Marin County Sheriff's Office posted the missing flyer to social media platform Nextdoor on Tuesday.

Law enforcement officials have not yet determined whether the teenager traveled to the Tenderloin district voluntarily or if she's been kidnapped.

The Tenderloin is the center of the fentanyl crisis in San Francisco. 

At the time of her disappearance, Mint was reportedly living with her mother.

Journalist Yashar Ali took to X, appealing to his followers for help in the search for the young teen, writing, "I don't ask for your help often, but I need it now. My friend's 16-year-old has gone missing. Please spread this far and wide, and if you have any information about their whereabouts, call the number on this flyer."