An Endangered Missing Advisory remains in effect for 18-year-old Riley Dawn Stevenson as authorities continue efforts to locate her.
According to the Middleton Idaho Police Department, Stevenson was last possibly seen in Sidney, Nebraska, during the late afternoon hours of May 24. Investigators say she may be traveling toward Kansas City and could be accompanied by another female.
Stevenson is described as a white female, 5-foot-6 and approximately 145 pounds, with brown hair and blue eyes. She was last seen wearing a blue t-shirt, tan pants, tennis shoes, and white over-the-ear headphones.
Authorities say Stevenson has been diagnosed with autism and has a mental capacity estimated between 12 and 14 years old.
No vehicle information or route of travel has been confirmed at this time.