LAKEVIEW, Ore. -

The sixth day of a wide-ranging search over some 4,000 square miles for a missing single-engine plane and its Idaho pilot ended tragically Wednesday with discovery of the wreckage.

Just before 3 p.m., the Oregon Wing of the Civil Air Patrol located a possible crash site and reported it to Lake County Incident Command.

An Oregon National Guard HH-60 Blackhawk helicopter was dispatched to the scene and confirmed the tail number of the airplane was that of Tony Nicholls'. The Meridian, Idaho man was found deceased, officials said.

The aircraft wreckage was found at 6,500 feet in elevation on the west face of Hart Mountain. The location of the crash was about 13 miles northeast of Plush, Oregon.

An investigation was under way at the scene while the FAA and the NTSB were being notified of the crash location.

Family members have been notified, officials said, adding that confirmation of the aircraft's occupant was assumed , pending positive identification.

Nicholls, 48, of Meridian, Idaho went missing Thursday night shortly after 5 P.M. in his 1978 Grumman Cheetah.

Skies were clear in the search area Wednesday, which encompassed more than 4,000 square miles. Lake County Sheriff Phil McDonald was at an incident command post is located at Adel, about 30 miles east of Lakeview.

The search area included diverse terrain in the high desert including tablelands and plateaus, heavily forested mountains, and canyons. There had been snowfall in some of the search area since Thursday night, which added difficulty in seeing a white airplane. But officials said the snow received last weekend was rapidly melting Wednesday as temperatures warmed upwards of 75 degrees in Lakeview.

Agencies and resources that worked the search include:

Lake County, OR Sheriff's Office

Oregon Emergency Management

Klamath County, OR Sheriff's Office

Emergency Airlift (Helicopter)

Josephine County, OR Sheriff's Office

Curry County, OR Sheriff's Office

Deschutes County, OR Sheriff's Office

Harney County, OR Sheriff's Office

Washoe County, Sheriff's Office

Siskiyou County, CA Sheriff's Office

Modoc County, CA Sheriff's Office

Bureau of Land Management

US Department of Fish and Wildlife

US Forest Service

Oregon Department of Forestry