ST. IGNACE, Mich. (AP) — Authorities believe they have discovered the wreckage of a small plane that crashed more than 20 years ago in remote northern Michigan.

National Transportation Safety Board spokesman Eric Weiss says national forest personnel found the wreckage Wednesday near St. Ignace in the Upper Peninsula.

A single-engine Piper took off Sept. 14, 1997, from Drummond Island in Lake Huron. The 45-year-old pilot, Mark Davies, and his wife, Janet, were heading to Howell, about 300 miles to the south. A flight plan wasn't filed.

The NTSB says the plane was seen on radar flying south, then turning and flying north. Then it disappeared.

A four-day search failed to find the remains of the couple or the plane.

St. Ignace is about 70 miles west of Drummond Island.