BETHEL -- A musher in the Kuskokwim 300 sled dog race scratched after suffering what may be frostbite on her eyeball, race officials said Saturday.

Brenda Mackey, one of four Mackeys in the race, reported at the Kalskag checkpoint that she had frostbite on her eye, race manager Zach Fansler said.

Mackey arrived there at 5:38 a.m. Saturday, according to her GPS tracker. Temperatures overnight were in the low single digits with winds gusting at 45 mph in Bethel.

"They took her immediately to the clinic," Fansler said. Health aides consulted with eye specialists in Bethel and Anchorage and decided she needed to be flown quickly to Anchorage, he said.

She may need surgery, Fansler said.

"Obviously our primary No. 1 concern is her safety, making sure she gets into Anchorage," Fansler said. Mackey's husband, Will, was with her at the checkpoint and was helping take care of her dogs.

No other serious injuries have been reported in a trio of races being run this weekend on a fast, hard, icy and wind-whipped trail.

The first 50 miles of the Kusko 300 and Bogus Creek 150 courses were rerouted from the Kuskokwim River onto the tundra, and mushers reported it was a rough ride. Some spilled making the initial turn from the frozen river onto the tundra.

The 300-mile race, which began with a field of 25 mushers, goes from Bethel to Aniak and back.

"We have an excellent tactical situation in the race itself," Fansler said. Father-and-son mushing champs Martin and Rohn Buser only rested an hour on their first Kalskag stop, a checkpoint where most mushers usually take a longer layover.

Defending champion and Bethel hometown favorite Pete Kaiser stayed in Kalskag four hours and defending Yukon Quest champion Brent Sass spent three hours there. Then Sass blew through Aniak without stopping as he headed onto the course loop to Whitefish Lake.

Racers must take a total of six hours of layover time between Kalskag and Aniak and can do it either on the way out to Aniak or the way back to Bethel.

Until the leading mushers all take their required rest and meet up again in Tuluksak, 50 miles from the finish, it's hard to know who holds the advantage, said Fansler said.