Question: What state did Arthur Treadwell Walden develop a sled dog in?
Sentence (from "Iditarod Trail Sled Dog Race"): In 2017, at the age of 57, Dallas's father, Mitch Seavey, is the oldest and fastest person ever to win the race, crossing the line in Nome in 8 days, 3 hours, 40 minutes and 13 seconds.
Relevant evidence: No