Mats Pettersson's lead dogs wait at the start line during the ceremonial start of the Iditarod dog sled race in Anchorage, Alaska, U.S. March 3, 2018. Mushers from around the world embark on Alaska's gruelling Iditarod Trail Sled Dog Race. (Photo by Mark Meyer/Reuters)





Four-time champion Jeff King at the ceremonial start of the Iditarod dog sled race in Anchorage, Alaska, U.S. March 3, 2018. (Photo by Mark Meyer/Reuters)





Sayonara a dog and musher Dave Delcourt prepare for the ceremonial start of the Iditarod dog sled race in Anchorage, Alaska, U.S. March 3, 2018. (Photo by Mark Meyer/Reuters)





Musher Tim Muto's team starts with breakfast before the ceremonial start of the Iditarod dog sled race in Anchorage, Alaska, U.S. March 3, 2018. (Photo by Mark Meyer/Reuters)





A dog from Jim Lanier's team is seen during preparations for the Iditarod dog sled race in Anchorage, Alaska, U.S. March 3, 2018. (Photo by Mark Meyer/Reuters)





Lars Monsen greets the crowd as he races down 4th Avenue during the ceremonial start of the Iditarod race in Anchorage, Alaska, U.S. March 3, 2018. (Photo by Mark Meyer/Reuters)





Tara Cicatello's team rounds the corner of 4th and Cordova during the ceremonial start of the Iditarod dog sled race in Anchorage, Alaska, U.S. March 3, 2018. (Photo by Mark Meyer/Reuters)





Dogs from Katherine Keith's team are seen at the ceremonial start of the Iditarod dog sled race in Anchorage, Alaska, U.S. March 3, 2018. (Photo by Mark Meyer/Reuters)





Shaynee Traska's team waits to unload during the Iditarod dog sled race in Anchorage, Alaska, U.S. March 3, 2018. (Photo by Mark Meyer/Reuters)





A 10 km prologue dog sled race on the eve of the 2018 Beringia dog sled race in Russia' s Far East; the prologue race is part of the 2018 Russian Winter Dog Powered Sports Cup in Petropavlovsk-Kamchatsky, Russia on March 4, 2018. (Photo by Yuri Smityuk/TASS)