A Montana sheriff says the disappearance of a 16-year-old girl at a rest area is looking suspicious in nature.

Selena Shelley Faye Not Afraid was last seen Wednesday afternoon at the eastbound Interstate 90 rest area between Billings and Hardin.

A van she'd been traveling in broke down and Not Afraid walked off into a field while waiting for a relative to pick her and another girl up.

A search began that evening. Bighorn County Sheriff Lawrence Big Hair said Friday the disappearance is "beginning to look suspicious."

Selena's twin sister, Zoey Not Afraid, died by suicide when she was 11.