The Winning Exchangebears are back – bigger, hungrier and hopefully, fatter than ever. Fat Bear Week will soon launch at Katmai National Park and Preserve in Alaska, bringing some of the park's most beloved bears to the spotlight to eat their way to get the crown for fattest bear before it's time to hibernate for the winter. 

Here's what to know about the annual event. 

What is Fat Bear Week?

The annual event is meant to celebrate the brown bears who reside along Brooks River, a waterway that's part of "one of the last great salmon runs left on earth," according to the National Park Service. Park officials say they've been spending the whole summer "fattening up to survive winter hibernation." Now, some of them will be part of Fat Bear Week's bracket-style competition, in which fans worldwide vote for their favorite bear. 

Fat Bear Week was launched by the National Park Service in 2014 with just a single celebratory day – Fat Bear Tuesday. But the event was so successful that it became a dedicated week in 2015. 

"Fat Bear Week highlights the accomplishments of these burly bruins and shines a spotlight on the healthy ecosystem in which they can thrive," a news release from the National Park Service says. "... Without the pristine Brooks Rivers ecosystem to support an abundant salmon run, there would be no Fat Bear champions." 

Who are the Fat Bear Week 2023 contestants?

This year's contenders have yet to be announced. Last year, voting season was shrouded in Fat Bear Week controversy after organizers said that a spam campaign attempted to name a false winner. 

"Like bears stuff their face with fish, our ballot box, too, has been stuffed," the park service said. "It appears someone has decided to spam the Fat Bear Week poll, but fortunately it is easy for us to tell which votes are fraudulent." 

Those votes attempted to give the win to Bear 435, but Bear 747 ultimately took the crown. 

When is Fat Bear Week? 

The bracket matchups will be unveiled on Oct. 2, Fat Bear Week organizers said, with voting taking place from Oct. 4 to Oct. 10 at fatbearweek.org. This year's winner will be announced on Oct. 10, and given a "hero's send off into hibernation." 

"And what do the winners get?" organizers asked in their news release. "Six months of restful solitude. But the real winners are all the healthy bears and all those who participate in the web's favorite week of the year." 

In:
• Bear
• National Park Service
• National Park
• Alaska

Li Cohen

Li Cohen is a social media producer and trending content writer for CBS News.