The 2021 Iditarod Trail Invitational marks the 20th anniversary of the world's longest-running and toughest winter ultra-marathon. We are so excited to celebrate this milestone with you, the fantastic community of athletes, fans and supporters who have made it possible. Registration for the race will open a month from today and we have no doubt ITI 2021 will be the best race yet! #iti #iditarodtrail #iditarodtrailinvitational #adventure #ultramarathon #alaska