Von Martin described a "slippery slope" that led him to become a dog musher. It started with one dog. Other dogs followed, all of them huskies rescued from animal shelters.

He said the animals needed little encouragement to pull a sled.

"It's all they want to do is run," Martin said.

Martin's dogs ran on Saturday, the first day of the Canines for Charity sled dog races atop Casper Mountain. The event continues today at 9 a.m., with races of different lengths beginning at Beartrap Meadow.

Martin's granddaughter, 8-year-old Casper resident Sydney Cooney, stood at the finish line and waited for Martin to finish his first race of the day, a six-mile sprint powered by four dogs.

Her own mushing debut - a 100-yard dash behind a single dog - was scheduled to begin later in the morning.

The charity event is an exception among sled dog races, according to Judy Martin, Von's wife. The two traveled more than 1,200 miles from their home in southwestern Washington to be with family and to attend the Casper races. Judy Martin said the event lacks the "highly competitive" atmosphere found elsewhere.

"I think it's phenomenal," Judy Martin said.

The 11th year event benefits the Arc of Natrona County, an organization that assists children and adults with developmental disabilities. Toni Hutchison, the organization's executive director, said the event raised $37,000 last year and is expected to do equally well this year.

Spectators with their own dogs and families with children crowded Beartrap Meadow Saturday morning in spite of chilly temperatures. Lanette Kimball, waiting for the afternoon's 22-mile race, said the temperature was actually warm for the dogs, who prefer temperatures of about 10 degrees Fahrenheit below zero.

Kimball and her sister Heather Sauers travelled from Idaho for the races. Three of their dogs recently returned from even more extensive traveling as filming for the Alaskan adventure film "Eight Below" concluded.

Apache, a red and white husky, rotated with three other dogs to play two roles in the film, Sauers said. Shorty and Noble each switched with two other dogs for their parts.

The movie is scheduled to open Feb. 17, but Sauers said she has seen it and is able to tell her own dogs apart.

She periodically stroked Apache's ears as the dog barked steadily beside her.

"Her best scene is when she's munching on some seagulls," Sauers said.

Sauers prepared on Saturday to compete in her first sled race, a one mile event. She said her goal is not to fall off or flip the sled.

Kimball, who races more frequently, has had her share of mishaps. She recalled being dragged for 12 downhill miles on one occasion as she clung to a tipped sled and tried not to let her team run away.

If a musher falls off a sled, the sisters said, the dogs likely won't stop.

The sisters' sled was built in 1987 and appeared to be somewhat rickety. Kimball said this quality is a virtue.

"The older they get, the easier they are to handle," Kimball said.

Kimball explained the braking options on a dog sled. A hook can be set in the snow as a sort of parking brake, resisting the dogs if they only pull forward. A rubber mat dropped between the sled's skis can slow the sled, and a metal spike suspended by a length of rubber cord can be stomped into the snow.

These options apply as long as the sled is upright and the driver is still present.

"It's like controlling an elephant with a feather," Kimball said. "The dogs are totally in control."

Reporter Anthony Lane can be reached at (307) 266-0593 or at anthony.lane@casperstartribune.net.