A missing woman from Alton died of environmental exposures, according to an autopsy done Wednesday.

Adria Jean Hatten went missing Jan. 21, and police found her body near Horseshoe Lake State Park on Tuesday, according to a news release sent out by the Madison County Sheriff's Office. An autopsy concluded there were no signs of trauma leading to her death, and no evidence of violence or foul play was found.

Routine alcohol and drug studies will have to be done, however, before a final ruling on Hatten's cause of death is made.

Hatten's car was found abandoned in a muddy field, about a mile-and-a-half from where her body was found. Her body was spotted from the air by an Illinois State Police air patrol unit. Volunteer search crews found a prescription pill bottle Saturday morning with Hatten's name on it, about 300 feet away from her car.