Sheriff's officials said the girl was semi-conscious when she was found Thursday night on Highway 20 by two people driving by.

Those people drove the girl to a nearby home and called 911. While in the ambulance, the teen passed out and later died.

Investigators said the teen is between 15 and 18-years-old. Since she did not have any identification, police have not been able to identify her.

Police also are trying to determine if the death was accidental. Until then, they are treating this as a possible homicide.

Rick Glancey, of the El Paso County Sheriff's Department, said police are canvassing the area near Highway 20 to find witnesses and gather evidence.

Glancey said the girl had no visible trauma and investigators are awaiting autopsy and toxicology reports.

It is still unknown if the teen lived at the home where she was taken, or if it was the home of the people who assisted her.

Stay with KFOX News for continuing coverage.