08/30/2011 04:21 EDT | Updated 10/30/2011 05:12 EDT

Desiree Oldwoman, Missing Alberta Autistic Woman, May Have Been Picked Up By Passing Driver


GLEICHEN, Alta. - An extensive search for an Alberta woman with autism has come up empty.

Mounties used an aircraft, dogs and about 40 searchers on the ground to search a three-square-kilometre area near the Siksika First Nation for Desiree Oldwoman.

The 21-year-old was last seen Saturday night at her residence on the First Nationabout 100 kilometres southeast of Calgary.

Oldwoman does not speak but can write her name, and police say she can't take care of herself.

She is five feet, four inches tall, weighs about 165 pounds, with short brown hair and brown eyes.

She was last seen wearing a brown sweater and black pants with a red stripe.