But when it comes to the Iditarod, family ties extend to the human side of the race.

As long as there has been an Iditarod, there have been three families shaping it, racing it, winning it -- the Redingtons, the Mackeys and the Seaveys.

In every race since the inaugural 1,000-mile run from Anchorage to Nome in 1973, someone from one of those families has entered it.

There's been a representative of the Mackey family every year except four.

There's been a Redington every year but six.

And though the Seavey clan has missed 18 races, the entry of 22-year-old Jen Seavey in the 37th annual race gives the family its sixth Iditarod musher -- one more than both the Redingtons and Mackeys. Jen is the wife of 21-year-old Dallas, the daughter-in-law of 2004 champion Mitch and the granddaughter-in-law of patriarch Dan.

Dan Seavey was there at the beginning of it all, as were Joe Redington and Dick Mackey.

Redington is the beloved "Father of the Iditarod," the man whose passion for sled dogs led to the creation of the race. All of Alaska mourned when he died in 1999 at age 82.

Seavey, who lives in Seward, is a former history teacher whose love of sled dogs meshed with his desire to see the traditional Iditarod trail -- established in 1908 to provide a route from the seaport of Seward to the gold fields of Interior Alaska -- preserved. He's the head of the Seward Trailblazers, a group that has worked for 30 years to establish a footpath on the historic trail that connects Seward and the Crow Pass trailhead in Girdwood.

And Mackey, who lives in Arizona but lived in Nenana during his mushing days, was one of the first to sign up for the first race, helped organize it and future races, and is the only one of the three to actually win the Iditarod. His stirring photo finish with Rick Swenson in 1978 remains the most dramatic victory in race history.

While Redington stayed off his sled in 1973 so he could organize and manage things, Seavey and Mackey were among 35 mushers who ran the inaugural race -- finishing third and seventh, respectively.

Asked at the finish line if he thought the race had a future, Seavey was skeptical. "I said, 'We'll be lucky if it lasts five years.' "

More than three decades later, the Iditarod is an iconic Alaska event. And the Redingtons, the Mackeys and the Seaveys remain enmeshed in its identity.

"It's a testament to sheer stupidity, I guess," Seavey said.

Find Beth Bragg online at adn.com/contact/bbragg or call 257-4309.