River & Sky Festival director Peter Zwarich says he thinks he knows the appeal behind the northern Ontario summer music event.

"At one point, everyone's gone on a camping trip in their younger days and wanted the whole world to be there," Zwarich said.

"That's where the festivities are born out of," he said. "Camp culture, campfires, staying up all night, playing music with your neighbours. That connection to land and water."

In a CBC Morning North interview, Zwarich announced four headliners for the July 20-23 festival on the Sturgeon River.

He said the four-day event kicks off with Wintersleep headlining Thursday night.

"At this point, Wintersleep is a Canadian icon, a real powerhouse band," he said. "We're hoping like last year with Hey, Rosetta, people check it out for one night, and hopefully we tempt them into a full weekend pass next year."

Friday night Timber Timbre brings its haunted folk sound to the stage.

"Timber Timbre's sound will fill the space at Fisher's Paradise that weekend," Zwarich said.

Toronto rockers PUP follow on Saturday night, and Zwarich thinks the band will provide a "high energy...roof-lifting experience."

"It's almost anthemic," Zwarich said of PUP's music. "We'll be hearing a young crowd singing back."

"Sunday will be a little more laid back," Zwarich said. "We want to send people off on a happy note."

River & Sky closes out with Weaves, a jazz-driven band from Toronto that has been drawing attention since their Juno Award nomination for alternative album of the year.

"It's like a new folk [music]," Zwarich said "it ranges from spoken word to strong vocals. It's a very interesting band."

Zwarich said the earlier-than usual release of the headliners is to give people a "lay of the land" of this year's festival.

"I think people like to plan their summer in the winter. Gives them something to hang onto," he said.

Zwarich estimates about 25 per cent of the 500 weekend passes are already sold.

He said he plans to announce more bands who will be performing through social media.

For more information on the River & Sky Festival, visit their website.