Federal investigators said Monday they are scrutinizing the unexpected landing of a private floatplane on a lake during the final day of the Ryder Cup golf competition at Hazeltine National in Chaska.

The Piper single-engine airplane with two men aboard gently put ripples into Lake Hazeltine about 2:30 p.m. Sunday near the 10th green during the international match between the U.S. and European squads.

Two canoeists were removed from roughly the same spot on the lake around the same time, and all four were cited by police. One of the canoeists said that none among the four had any idea that the lake was temporarily off-limits. He said he intends to fight the petty misdemeanor charge, which carries a fine of up to $300.

On Tuesday, police released the identities of the four. On the plane were licensed pilot Dean Scott Johnson, 60, of Chanhassen, and James David Render, 63, of Wayzata. In the canoe were Ryan James Hough, 34, of Waconia, and Craig Jonathan Bardal, 31, of Chaska.

Ryder Cup attendee Jeff Kouba said he was watching the action on the 10th green when he saw two men exit the seaplane, sit down on the floats and watch the golfers for close to an hour.

“We thought it was a pretty good idea to watch from there,” said Kouba, of Blaine, who bought a ticket like thousands of others for the right to watch on solid ground. “They had a plane, the next best thing.”

Another spectator, Greg Williamson, who traveled from Port St. Lucie, Fla., for the Ryder Cup, said he and others around him were thinking, “Is this legal? Are there going to be cops coming?”

The pilot and his passenger “just sat there watching the golf tournament like nothing was ever wrong.”

The aircraft is registered to a residence about 2 miles southeast of the lake, according to the Federal Aviation Administration (FAA). John Trusheim is a licensed pilot who lives at that address, but he said in a brief telephone conversation Monday that he knows nothing about what happened and hung up the phone.

Police Chief Scott Knight said a city ordinance was in place prohibiting any activity on the lake during the event. 

The two canoeists arrived on the lake shortly after the plane landed. Hough acknowledged being one of those canoeists and said he got quite close to the 10th green not realizing that they were doing anything illegal.

The pilot also claimed to not knowing he made a mistake, Knight said, “but I can’t imagine he didn’t.” The chief further commented that the pilot’s actions were “imbecilic” and “stupid.”

The ordinance quieting Lake Hazeltine for the event was passed Aug. 1 by the City Council and later published in the Chaska Herald. It also was posted on the Chaska city website, according to Senior City Clerk Denise Wetzel. She said she was unaware of the ordinance being publicized in any other way. The Herald mentioned it on Page 34 of a Ryder Cup special section that was distributed in Chaska and some nearby suburbs.

Knight posted on Facebook a 2-minute video about “important information to share” about access to the golf course and a warning about bringing restricted items to the Ryder Cup. He did not mention any limits on access to the lake.

Knight was off Monday and other police officials declined to comment.

“We had no clue the water was off limits,” Hough said. “We were told an ordinance was passed in August and printed in the local paper. We don’t get the local paper and do not live in Chaska. We did not trespass to enter the lake,” which offers no public access.

Hough said he intends to fight his citation in court, pointing out that “there wasn’t even any signage anywhere around the lake notifying it [as] being a prohibited area.”

“If Chaska was so serious about no one being on the water, how were a couple of locals like us able to paddle right up to the green? Thank God we weren’t terrorists or a lone wolf gunman.”

Hough said he chatted with the men on the plane soon after they were all pulled off the lake. “They [said they] checked the FAA rules ahead of time. Hazeltine Lake is clear for plane landings. There were no restrictions.”

FAA spokeswoman Elizabeth Isham-Cory confirmed her agency is looking into the plane incident and added that “there were no TFRs [temporary flight restrictions] over” Hazeltine while tens of thousands of fans watched the competition, won by the U.S. team. Ryder Cup security included an official from the FAA watching radar.