When Galbraith Mountain turns white, the mountain bikers keep coming.

About half the regulars ride bikes in the snow on the hill east of Bellingham, which is often known as Lookout Mountain, says Darren Clark, vice president for Whatcom Independent Mountain Pedalers. “You can hear the whoops and hollers of them echoing through the wood,” says Bruce Brown, owner and author of the mountain biking Web site www.galbraithmt.com.

Russ Barlow, 33, who works for Clark at Clark’s Cycles, says he rides in the snow because he rides three times a week, no matter what the weather.

But snow is fun.

“You end up pushing up some of the hills but on the way down it’s reckless pinball good times,” he says.

When the ground is covered in white he prefers to stick to trails with smoother surfaces — it isn’t a time to be tangling with roots and rocks.

Brown says snow takes well-known trails and adds an element of challenge.

“It takes the familiar and beloved and makes it completely new.”

And a layer of white adds majesty to Galbraith Mountain’s scruffy mixture of low woods and clear cuts.

“Sometimes it’s breathtakingly pretty,” Brown says.

Brown says that trails going through wooded areas have less snow on them, and are easier to tackle on snow days, though Clark sees one drawback: “There’s snow on the trees. You go through the trees and all of a sudden there’s snow down your back.”

Barlow says mountain bikes don’t need special gear to tackle snow — knobby mud tires are fine. But people should dress warmly, wearing winter gloves, neoprene booties over shoes, wool socks, and a cap under the helmet that covers the ears.

It’s also important to seal off holes in bike helmets, either with a cover or with tape.

“If you get snow down in your vents, you get the ice cream headache pretty bad,” Barlow says.