After 14 days of flyovers in Katmai National Park and Preserve, the search has been called off for a missing plane and its four occupants.

The National Park Service delivered the news late Friday to friends and family members of pilot Marco Alletto and three passengers -- NPS employees Mason McLeod and brothers Neal and Seth Spradlin. The floatplane, owned and operated by Branch River Air Service, disappeared Aug. 21 after taking off from Swikshak Bay.

Regular park patrols will stay on the lookout, and all pilots flying around the area are encouraged to report anything helpful they may see, according to a NPS statement Friday evening.

"All of us here at Katmai National Park, and in the communities of Naknek and King Salmon, are devastated by this tragic incident," said Katmai National Park and Preserve Superintendent Ralph Moore in the statement. "To lose such fine people hurts deeply. Our hearts go out to the families of Neal, Seth, and Mason and to our friends at Branch River Air."

Searchers had hoped to locate people who may have seen the plane flying that day, which would have helped narrow the 14,000-square-mile search area. But no substantive reports came in, according to NPS Ranger Adrienne Freeman.

"The longer we have aircraft in the air, the more risk we run of injuring someone in an aviation accident," Freeman said.

Nearly 60,000 flight miles -- far enough to fly around the earth two and half times -- were logged scouring the mountainous terrain for signs of the plane. Just over $1 million was spent through the combined efforts of  NPS and military search teams.

The two-week searchinvolved volunteer planes and pilots, as well as the NPS, U.S. Fish & Wildlife Service, Alaska Air National Guard, Alaska State Troopers, the Alaska Fire Service, U.S. Coast Guard, the Civil Air Patrol, U.S. Department of the Interior Aviation Management Directorate, Federal Aviation Administration, and the National Transportation Safety Board.