A repost by the Professor.
Here is another excellent blog post on fat bike touring in Alaska on the Iditarod Trail from Knik to McGrath. It is in two parts. Enjoy.
http://www.topofusion.com/diary/2013/03/08/great-alaskan-adventure-aka-iditabunny-part-1/
http://www.topofusion.com/diary/2013/03/09/great-alaskan-adventure-part-2/