A single-engine plane crashed Sunday in mountains east of Winter Park, killing two people, officials said. The victims were the only people on board, Federal Aviation Administration duty officer Andee Curran said. The plane had taken off from Kremling and was on its way to Boulder.The 1969 Citabria 7KCAB, was listed as being registered to a Coe Hargraves, who recently sold it. He said the two-seater plane was in good condition at the time of sale. "Both pilots were well-qualified and certified. The plane was in good and legal mechanical condition," Hargraves said. "There was nothing wrong with the plane. There was nothing wrong with the pilots."Hargraves declined to identify the two victims but said they were from Boulder. He said investigators will have to determine why the plane crashed. Boulder County sheriff's officials said the plane went down about 7 a.m. Sunday in the Indian Peaks Wilderness Area near the Skyscraper Reservoir, near the line between Boulder and Grand counties. The location is well known to pilots who cross the Continental Divide and has been the site of several fatal plane crashes.Two Denver-area couples who were camping nearby saw the crash and a member of the party hiked to a an area where cell phone service was available to call in the accident.