Anchorage to Nome, Alaska
The event was first held in 1973. It is a long distance endurance event, covering approximately 1,000 miles (1,600 km). A famous run from Anchorage to Nome in 1925 carried serum to help in a threatened diphtheria epidemic.
What natural ice 1,212.5 metre (3,978 ft) long racing sled run in the Swiss town of St. Moritz, based on a river, was built in 1884?