March 20 is the 20th anniversary of Libby Riddles becoming the first woman to win the Iditarod Trail sled dog race.

Here are three things you might not know about the Iditarod.

• It’s named after the Iditarod National Historic trail, which runs from Seward to Nome via the ghost town of Iditarod.

• It is run in honor of the 1925 serum run which was a sled dog relay to deliver a diphtheria antitoxin to Nome to fight an outbreak.

• In the inaugural race in 1973, 22 mushers completed the race, which was won by Dick Wilmarth, who finished in 20 days, 49 minutes, 41 seconds.