A sightseeing flight ended in tragedy, searchers learned this week, as they discovered all four people aboard killed.

The small plane that began its cruise on Sunday was found by a Homeland Security helicopter in the Revais Creek area south of Dixon on June 30 about 2 p.m. near where the Federal Aviation Administration had made its last GPS and radar contact with the plane.

The plane was intact and on level ground but surrounded by steep and heavily timbered terrain at 7,700 feet elevation, and the helicopter couldn't land. A helicopter from Malmstrom Air Force Base was used to ferry Sanders County undersheriff Rube Wrightsman to the site, where he rappelled down to the plane and confirmed there were no survivors.

On board were Erika Hoefer and Melissa Weaver, reporters hired by the Daily Inter Lake last December; Missoula pilot Sonny Kless, who grew up in Bigfork; and Brian Williams, a second-year law student at the University of Montana.

Family and friends of the victims gathered at the command center established at the National Bison Range were notified of the outcome shortly before 5 p.m.

Kless had rented the blue-and-white 1968 Piper Arrow single-engine plane in Missoula, flew north with Williams and departed Kalispell City Airport with the two women about 1:30 p.m. Sunday.

Radar data shows the plane flew north along the Whitefish Range, entered Glacier Park airspace, then headed south along the Swan Range and across Flathead Lake to the Bison Range.

Kless last made radio contact with GPI Airport at 2:11 p.m. Hoefer last updated her Facebook page on 1:40 p.m., saying she was flying over Glacier Park. Weaver and Hoefer text-messaged each other at 3:47 p.m., and the plane went off the radar screen at 4:02 p.m.

Radar indicated the plane flew over the Bison Range about 300 feet above the ground, and witnesses near the search area reported seeing a small plane flying 20 to 30 feet above the Flathead River.

More than 100 people using planes, helicopters, ATVs, horses and boats with sonar were involved in the search. The focus narrowed to the area near the site of the crash after an eyewitness reported seeing a blue-and-white plane rising out of the Flathead River corridor, throttling up and barely clearing a nearby ridge.

The National Transportation Safety Board has been notified and will take over the investigation, and the Federal Aviation Administration also has been contacted, Wrightsman said.