ELLENVILLE, N.Y. (AP) — It's been three decades since a Hudson Valley teenager disappeared in the Minnewaska State Park Preserve, and state police haven't closed the books on the case.

Seventeen-year-old Joseph Helt was reported missing on Jan. 17, 1987 by his mother. Lee Ann Helt said her son did not return home after going out with friends the previous night.

Joseph Helt was last seen with three friends after their vehicle became disabled in some snow at Sam's Point Preserve, a popular hiking spot.

Troopers say Helt walked off in the snow and disappeared. He was last seen wearing a camouflage jacket, t-shirt, long sleeve thermal shirt, grey hooded sweatshirt and white high-top tennis shoes.

Anyone with information on the case is asked to contact Troop F at: 845-344-5300.