Search teams braving bad weather and daunting terrain reached the wreckage of a crashed U.S. military reconnaissance plane and recovered four crew members' bodies, authorities said today.

Working in visibility of less than five feet due to dense clouds and fog, U.S. and Colombian investigators located the tail number of the De Havilland RC-7 aircraft, confirming it was the missing U.S. plane. By late today, they had recovered the bodies of four of the seven crew members--five Americans and two Colombians--from shattered debris lying in thick jungle on a steep slope in an area of southern Colombia controlled by Marxist rebels.

The four bodies were flown to a Colombian military base while a search continued for the three others, who are presumed dead, as well as for clues to what caused the aircraft to slam into a remote ridge early Friday during an anti-narcotics mission.

"Our number one priority is still to locate the three remaining crew members," said Air Force Capt. Jack Miller, a spokesman for the Southern Command, which is based in Miami and responsible for U.S. military operations in Latin America and the Caribbean.

The crash of the four-engine, propeller-driven plane marked the first time that American troops have been killed in Colombia's U.S.-supported war against drug smuggling and Marxist-led guerrillas who often protect the traffickers.

During a two-day visit to Colombia this week that was planned before the RC-7 was reported missing, President Clinton's top counter-narcotics official, Barry R. McCaffrey, a retired general, said the aircraft apparently crashed into an uncharted mountain while flying in inclement weather. Officials said the crew of the plane--which was carrying infrared sensors and eavesdropping equipment--gave no indication that they were being fired on by guerrillas before losing contact with controllers.

Southern Command officials said more than two dozen Colombian and U.S. military personnel were lowered from a helicopter late Tuesday onto a peak more than 900 feet above the debris field. It took the team about three hours to descend the ridge. But a Colombian Defense Ministry source said that Colombian troops walking from nearby towns arrived at the crash scene first, and that the helicopters delivered additional personnel only this morning.

The crash area is controlled by rebels of the Revolutionary Armed Forces of Colombia. The Colombian source said some insurgents were spotted in areas around the wreckage but there were no reports of clashes. The rebels have a strong presence throughout the Putumayo and Caqueta regions, where two-thirds of Colombia's coca is grown.

This South American country of 37 million people supplies an estimated 80 percent of the world's cocaine and more than two-thirds of the heroin consumed in the United States.