How can I register for the Route 66 Marathon? Johnny Spriggs November 09, 2016 13:23 Updated Follow All participants can register online at: www.route66marathon.com There is no mail-in or offline registration for the Williams Route 66 Marathon. Related articles When is the last day to register for the Route 66 Marathon? What is the deadline to register for the charity program? What is your mailing address Where do I park on race day? My race is sold out. Is there a waiting list or any other way to get in this year? Comments 0 comments Article is closed for comments.