The 54th annual Equinox Marathon is this Saturday in Fairbanks. A new book “The Equinox: Alaska’s Trailblazing Marathon” explores the story of the interior Alaska running classic, and its surprising significance in marathon history. KUAC’s Dan Bross spoke with the the book’s author: 5 time Equinox Marathon champion Matias Saari about why the event is more than just a race.