Close to 100 emergency personnel, including nearly 60 firefighters, responded to the intense blaze at the White Point Beach Resort.
Staff Sgt. Jeff Wells of the Liverpool RCMP said the lobby of the resort was engulfed in flames and it appeared the main structure would be destroyed. There were no reports of people being injured in the fire.
"We've got it under control, but the flames are quite high," he said at the scene of the hotel outside Liverpool.
"This is a major structure fire...and I think the main building will be lost when this is over."
A guest at the resort reported seeing flames shooting out of the main building, reaching 15 metres into the sky.
The fire also appeared to have spread to an adjoining building that houses a restaurant and a meeting room.
Wells said all guests had been evacuated, with many hovering outside under blankets as they watched the blaze.
He urged people to stay away from the site, since trucks were having trouble getting in because of traffic.
Wells said they didn't yet know what caused the fire, but a guest said it seemed to start at around 1:30 p.m. It was being doused by crews from about nine fire services who were using ladder trucks.
Wells added that an investigation into what sparked the blaze will begin in the next few days.
The resort was built in 1928 as a private hunting and fishing lodge, starting with a few log cabins on the beach, an eight-room main lodge and a dining room.
Over the years, the hotel expanded with tennis courts and a golf course, all tucked along the shore of a white sand beach.
The resort was to undergo renovations early next year. It was home to over 100 employees.
Past visitors took to the resort's Facebook page Saturday evening to voice their dismay and express their support for those who run the lodge.
(The Canadian Press/CKBW)