The Yukon Quest 1,000-mile International Sled Dog Race, or simply Yukon Quest, is a sled dog race run every February between Fairbanks, Alaska, and Whitehorse, Yukon.
 Because of the harsh winter conditions, difficult trail, and the limited support that competitors are allowed, it is considered the "most difficult sled dog race in the world", or even the "toughest race in the world".
A sled dog race was included as a demonstration event at the 1932 Winter Olympics in Lake Placid.
 5 contestants from Canada and 7 contestants from the United States competed.
 The event, run under the rules of the New England Sled Dog Club, ran twice over a 25.1 mile (40.5 km) long course.
 With six dogs per sled, each sled took off at three-minute intervals, and intermediate times were given to the mushers at 4 miles (6.44 km), 10.6 miles (17.06 km), and 22.46 miles (36.14 km).
The Junior Iditarod Sled Dog Race, or Jr.
 Iditarod, is a 148- to 158-mile (222 km) sled dog race for mushers between the ages of 14 through 17, which is patterned after the 1,150-mile Iditarod Trail Sled Dog Race that is said to be 1,049 miles.
 The race is held outside Anchorage in the U.S. state of Alaska, and was the first long-distance race for juvenile mushers.
Arthur Treadwell Walden (May 10, 1871 – March 26, 1947) was a Klondike Gold Rush adventurer, dog driver and participant in the first Byrd Antarctic Expedition.
 He is also known as an author and developer of the Chinook sled dog breed.
The list of sled dog races contains dozens of contests created by supporters of mushing, the sport of racing sled dogs.
 It is unknown when the first sled dog race was held.
 Humans have domesticated dogs for thousands of years, and sled dogs have been used for transportation in Arctic areas for almost as long.
 The first sled dog race to feature a codified set of rules was the All-Alaska Sweepstakes, which first took place in 1908.
 This was followed in 1917 by the American Dog Derby, which was the first sled dog race outside Alaska or the Yukon.
 In 1932, sled dog racing was a demonstration sport at the 1932 Winter Olympics in Lake Placid, New York, but was not included in future games.
The Hope Race or Hope Sled Dog Race is a defunct international sled dog race between Nome, Alaska and Anadyr, Russia, across the Bering Strait.
 The race was established in 1991, shortly after the fall of the Soviet Union, and according to information on the race's (now inactive) Web site, was run as recently as 2004.
 Racers covered 1,200 miles, but did not actually race across the Bering Strait.
 Teams instead were shipped across the strait on boats and raced on land.
 In 1995, Alaska musher Bob Holder became the only person to compete in the Hope Race, Iditarod Trail Sled Dog Race, and Yukon Quest in the same year.
King moved to Alaska in 1975 and began racing in 1976.
 A successful sled dog racer, he won the Yukon Quest in 1989, and the Iditarod Trail Sled Dog Race in 1993, 1996, 1998, and most recently, in the 2006 Iditarod.
 Five other mushers have won the Iditarod four times (Dallas Seavey, Martin Buser, Susan Butcher, Doug Swingley, Lance Mackey) and only one, Rick Swenson has won it more often (five times).
 King was 50 years old when he won the 2006 Iditarod, which made him the oldest musher to win the event, a distinction he held until 2013 when Mitch Seavey won at age 53.
 As of 2015, he has competed in 26 Iditarods.
 His "Idita-Rider" for the 2005 Iditarod was a child sponsored by the Make-a-Wish Foundation.
 King has also won many other sled dog races.
 He continues to race and has a kennel near the entrance of Denali National Park.
The Chinook is a rare breed of sled dog, developed in the state of New Hampshire during the early 20th century.
 The Chinook is New Hampshire's official state dog.
The Alpirod is a defunct 1000 km sled dog stage race in Southern Europe.
 Its name comes from a combination of the Alps, where the race took place, and the Iditarod Trail Sled Dog Race, upon which the race was based.
 The competition consisted of a 14-day stage race in 11 cities in four countries: Italy, Germany, Austria and France.
 The competition consisted of multiple short races separated by evening breaks, similar to cycling's Tour de France.
 At the time, it was the largest sled dog race outside North America.
 The race was organized by Armen Khatchikian, an Italian Iditarod competitor who hoped to bring a form of that race to Europe.
 It first took place in 1988, and the inaugural race was won by Alaska racer Joe Runyan.
 In 1989, the race was won by Kathy Swenson.
 She was the first woman to win the race.
 In 1990, Alaskan Roxy Wright Champaine won the race, becoming the third American winner.
 In 1992, the race was won by Nenana, Alaska musher Jacques Philip, who went on to win the race three times.
The Iditarod Trail Sled Dog Race is an annual long-distance sled dog race run in early March from Settler's Bay to Nome, which takes place entirely in the US state of Alaska.
 Mushers and a team of 16 dogs, of which at least 5 must be on the towline at the finish line, cover the distance in 8–15 days or more.
 The Iditarod began in 1973 as an event to test the best sled dog mushers and teams but evolved into today's highly competitive race.
 Then a record, the second fastest winning time was recorded in 2016 by Dallas Seavey with a time of 8 days, 11 hours, 20 minutes, and 16 seconds.
 As of 2012, Dallas Seavey was also the youngest musher to win the race at the age of 25.
 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.
 Dallas finished second, two hours and 44 minutes behind.

Question: What state did Arthur Treadwell Walden develop a sled dog in?
Answer: New Hampshire