Which kind of race is the Yukon Quest, held annually in Canada and the United States?

The Yukon Quest, formally the Yukon Quest 1,000-mile International Sled Dog Race is a sled dog race scheduled every February since 1984 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"—"even tougher, more selective and less attention-seeking than the Iditarod Trail Sled Dog Race." The originator envisioned it as "a race so rugged that only purists would participate."

The route runs on frozen rivers, over four mountain ranges, and through isolated northern villages. Racers cover 1,016 miles (1,635 km) or more. Temperatures commonly drop as low as −60 °F (−51 °C), and winds can reach 50 miles per hour (80 km/h) at higher elevations. Because it begins a month earlier than the Iditarod, the Quest is a colder race, and is run on shorter solar days and through longer, darker nights. Sonny Lindner won the inaugural race in 1984 from a field of 26 teams.

The longest race time was in 1988, when Ty Halvorson took 20 days, 8 hours, and 29 minutes to finish.

The 2020 race finished on schedule despite the incipient COVID-19 pandemic, but the 2021 race has been modified to take place only on the American side of the border.