Why Is Everyone Obsessed With Fat Bear Week? We Explain.

Published September 14, 2025 03:04PM

Fat Bear Week, the annual March Madness-style competition that lets viewers vote for the fattest brown bear in Katmai National Park and Preserve, starts early this year. Beginning on September 17, the actions kicks off with Fat Bear Week Jr., a showdown between the park’s chunkiest cubs. The main event kicks off on September 22, and culminates on September 30, when the National Park Service and Explore.org will officially crown the biggest chonk of 2025.

Since launching in 2014 as Fat Bear Tuesday, Fat Bear Week has grown to be arguably the biggest bear-centric event of the year and one of the NPS’s most popular initiatives, with more than a million people casting votes in last year’s contest. Get ready for the action with this curated reading list, featuring our best reporting about the fall’s biggest competition.

What is Fat Bear Week?

The Implausible Fame of Fat Bear Week

It started as a jokey social media contest; nowadays, it’s a cross-border social media phenomenon that’s earned coverage everywhere from CBSc to the New York Times. How did Fat Bear Week make the jump from niche to primetime?

How Do the Fat Bears Get So Fat, Anyway?

Over the course of a couple months of fall, the brown bears of Katmai can literally double their weight, eating around the clock to pack on as much weight as possible in time for their winter snooze. We break down the miracle of biology that lets them do it.

A Hall of Champions

The winners of Fat Bear Week are some of the largest terrestrial predators on the planet, and each one is a specimen of just how big bearkind can get.

480 Otis Wins Fat Bear Week

The original Fat Bear Week champion wasn’t just big, but showed remarkable longevity.

747 is Your 2020 Fat Bear Week Champion

The name was apt, with this 1,400-pound champion looking more like a jumbo jet than an animal.

Holly Wins Fat Bear Week 2019

One of the most experienced mamas at Brooks Falls, Holly was the last champion of the teens.

409 Beadnose, Winner of Fat Bear Week

Fan-favorite Beadnose had raised four separate litters of cubs by the time she nabbed her second title in 2018

The Otis Collection: Tribute to a Champion

Of all the bears at Brooks Falls, none boasted as many titles as Otis, who won the annual poll a record four times. But no king can reign forever.

Meet Otis, the Fattest Bear

Just because they’ve counted you out doesn’t mean you’re done: Otis was 20 years old—elderly, for a bear—when we profiled him following his third victory in 2016. We didn’t know it then, but he wasn’t even done.

Why Otis Is the Best (and Oldest) Bear of Fat Bear Week

Otis captured his final Fat Bear Week title in 2021, when he was 25, about as old as brown bears live in the wild. With his teeth worn to stubs and the best fishing spots in the river taken over by younger, bigger bears, how did this veteran continue to get so big? It came down to experience, patience, and the ability to snooze seemingly everywhere.

Farewell to Otis, the King of Fat Bear Week

In 2024, when Otis was roughly 28, he failed to show up to Brooks Falls for the fall season. Given his age, it seemed likely that the big man had taken his final bow. We eulogized the best to ever do it.

The Wild Side of the Week

It’s not all salmon and roses. Sometimes, the drama captured on bear cams is about life and death.

Fat Bear Week Fans Shocked After One Bear Kills Another on Livestream

The cameras were rolling in 2024 as one familiar bear, 469, killed another, 402, seemingly drowning her during a scuffle before consuming part of her body. For viewers, it was a reality check about what spectating the daily life of one of the biggest bears on Earth really meant.

This Was the Darkest Fat Bear Week Yet

Infanticide, an on-camera death, and a final grudge match: 2024 will stand out as the year that viewers got an unvarnished look into the less savory side of being a bear. As we wrote, maybe that’s a good thing.

Bear Cam Viewers Spot Lost Hiker in Katmai National Park

Viewers of Katmai National Park’s bear cams usually expect to see bruins gorging themselves on salmon and scuffling. But one day in 2023, users watched as a man walked up to one of the cameras and mouthed the word “help.”

For the Superfans

You know the contenders, you know the science, and you already know who’s going to get your vote. Dive deeper with these stories.

Eat Like a ‘Fat Bear’ with These 6 Salmon-Forward Trail Recipes

Forget nachos. At this year’s Fat Bear watch party and/or campout, honor the creatures of the hour with these six recipes based on the bears’ favorite food.

A Bear Enthusiast’s Guide to Katmai National Park

Tired of watching the action online? See it yourself with our guide to safely visiting and backpacking through their home range.