A Canadian man pleaded guilty Wednesday to accusations he flew tons of drugs via helicopter over the U.S.-Canada border in north Washington, and now faces more than five years in prison.

Henry Rosenau, 61, of Armstrong, British Columbia, struck a plea deal that had him plead guilty to a charge of conspiracy to import marijuana, which carries a minimum sentence of five years in prison and up to 40 years in prison, the U.S. Attorney’s Office said.

Rosenau admitted to flying dozens of loads of marijuana into remote areas in Western and Eastern Washington, Idaho and Montana between 2000 and 2005, the Attorney’s Office said. He also flew Canadians across the border and into the U.S. to work as “offloaders” and transporters for the loads of drugs.

“Rosenau and his co-conspirators thought they had the perfect plan to smuggle drugs into the United States, but obviously they were mistaken,” said Brad Bench, a special agent in charge of the Homeland Security Investigations team that identified Rosenau and others involved in drug smuggling during Operation Frozen Timber.

The Attorney’s Office posted video of some of the drug drops online.

Royal Canadian Mounted Police caught Rosenau in 2005 after he returned to Canada from making a drop in the U.S., the Attorney’s Office said. Officers checked the cockpit of the helicopter and found a loaded handgun, night vision goggles, two satellite phones and a GPS device with tagged locations of known marijuana drop sites.

More than 40 people were indicted as a result of Operation Frozen Timber, the Attorney’s Office said. Teams from the U.S. and Canada seized more than 17 drug loads, including one in February 2005 in which officials found five suitcases packed with 169 kilograms of cocaine. Another bust in September 2005 in Puyallup yielded more than 1,200 pounds of marijuana.

Rosenau is scheduled to be sentenced October 5.