Several dozen mushers and their dog teams hit the trail Sunday for the annual John Beargrease Sled Dog Marathon in northeast Minnesota.

The main event is a 300-mile race that starts in Duluth, winds its way along the North Shore and Gunflint Trail, and ends at Grand Portage, Minn.

Some years the teams have to contend with bitterly cold conditions. This year? Not so much. Temperatures at the start should be about 30 degrees above zero.

Race spokesperson Monica Hendrickson said teams will have to adjust for the conditions.

"We're anticipating mushers will probably change their strategy a little bit, and probably run in the evenings when it's cooler," she said. "There's mandatory rest times and then they can figure out when their team needs to rest (and) what's best for their dog team. It's kind of like a game of chess a little bit. There's a lot of strategy that goes into it. And ... obviously the bond between a musher and their team, it is a very close bond. And those mushers know what's best for the dogs."

Fourteen teams are signed up for the 300-mile race, including defending champion Blake Freking of Finland, Minn. Other past Beargrease champions in this year’s field include Nathan Schroeder, Ryan Anderson, Ryan Redington and Keith Aili.

More than 40 other teams will take part in shorter events.

The Beargrease is noted for the challenge of its hilly course. It's not as long as some races in Canada and Alaska, but Hendrickson said the dogs and mushers have to navigate the rocky topography of the North Shore's Sawtooth Mountains.

"A lot of people say, 'Oh, it's only 300 miles' — until they get into that mountain range. They don't realize how many hills they have to run up and down," she said. "So the musher can't ride on the back of the sled. (They have) to run with his team or her team. And it's a very physical race and it's pretty tough. It's fun to see Canadian mushers and Alaskan mushers that come and run it for the first time. And they may come into some of the checkpoints and they're like, 'Oh, my gosh, those hills are insane.' So our local mushers have a little leg up on them."

Spectators are welcome at the start, finish and checkpoints in between. But for those who can't go in-person, Hendrickson said the race is increasing its online coverage this year.

"Think about like an Olympics or Tour de France-type situation where they will be covering the race from beginning to end in-studio. And then we have a production team here in Minnesota with us. We have about 30 people that will be traveling with the race. We'll have drone footage, helicopter footage (and broadcast) live at every checkpoint."

The top teams are expected to cross the finish line in Grand Portage on Tuesday afternoon or evening.