Susan Butcher has won the Iditarod Trail Sled Dog Race -- an 1,100-mile trek across Alaska's frozen tundra -- four times, but the mother of two faces her toughest race yet as she battles a rare and deadly form of leukemia.
And, she's launched an awareness campaign to fight for all people who need bone marrow transplants.
"A friend of mine said, 'Leukemia hasn't met Susan Butcher yet,' and I agree with her," Butcher said. "It's going to have to fight awful hard if it wants to take me."
Thanks to www.alaska.org for additional video and information on the Iditarod.
Butcher has faced death head-on before -- during a training run, she and her sled got stuck in a frozen creek. She would have died were it not for her faithful dogs.
"I was just trying to hold myself up on the ice until I realized I was losing my strength and I was just going to sink under, and I thought, 'What do I want to do with the last seconds of my life?'" said Butcher, who still raises and trains dogs, even though she gave up racing more than a decade ago.
"And I said, 'Well, I want to look at my dogs.' And I turned, and all seven of them were riveted on me, of course, and I didn't say a word. I didn't even think it. They came over to me, and I grabbed a hold of them and they pulled me out."
Two long braids were Butcher's trademark -- and indeed the face of the Iditarod -- but she has lost her hair to chemotherapy.
"I've always wanted to shave my head so I love this hairlessness," Butcher said.
Her iconic hairstyle may be gone, but her determination remains.
"You look at it face on, and it looks pretty scary. And then that just gives me more of a fighting spirit," she said.
"She is determined," said her husband, David Monson. "She can climb a mountain one step at a time."
Butcher is lucky. She has found an unrelated donor for her bone marrow transplant. She says she's heartsick at the hospital when she's surrounded by others who may not be as lucky.
"What saddens me in this is to think of somebody laying in that ward like I am and being told, 'I'm sorry but we can't find a match for you.'"
She has helped organize an awareness campaign for Mother's Day about the need for people to register as bone marrow donors.
"Next week, somebody who I've never met is going to give me the gift of life," she says in the public service announcement. "I'm getting a bone marrow transplant. … You can save someone's life."
Butcher had to think about the unthinkable -- how she wants her daughters, Chisana, 5, and Tekla, 10, to remember her.
"I'm journaling to the kids, you know, writing things to them in case I'm not here so they have my words to know who I am and what they mean to me," Butcher said. "And I hope they never get to read it."
For Butcher, the hardest part of the transplant will be the time spent away from her family, said her friend, Susan Roody.
"The fact that right now she is in isolation. Her kids can't touch her for about a week," Roody said. "That is really hard when you're the kind of devoted mom that Susan is."
Hospitalized in Seattle, Butcher has thought long and hard about her daughters.
"They're both strong girls, and it's going to be a terrible time for them if I die, but they're going to be great people, amazing women," she said.
The girls, who have been wearing their hair in braids to honor their mother, have been thinking about Butcher a lot, too.
"She is always there to comfort me if I have a bad dream or if I start crying," Tekla said. "And she always gives me hugs at the right times."
In her biggest race yet, Butcher says she is determined to win.
"I pay no attention to the odds and, you know, I'm planning on getting cured."
ABC's Brian O'Keefe reported this story for "Good Morning America."