145: The Lake Waramaug 100K

The first certified 100 km race in America was held at Lake Waramaug, Connecticut, in 1974. Today it remains as the oldest 100 km race in the country and the second oldest American ultra still held. For many years in the late 1970s and throughout the 1980s, it was the unofficial national championship for the 100 km distance and the best ultrarunners in the U.S. made their pilgrimage to Lake Waramaug to test their abilities on the 7.59-mile paved road loop around the lake.

Before 1974, the 50-mile or 100-mile distances had been the America's “standard” ultra distances. But most of the ultras held during the 1970s were of odd lengths. There were a few road 50 kms, such as those put on by the AAU in Sacramento. But in the New York City area, the hotspot for ultramarathons put on by Ted Corbitt (1919-2007), of the New York Road Runners, had a large variety of ultra distances during the 1960s and early 1970s. San Francisco had been the scene of multiple 32 milers. Racing around Lake Tahoe for 72 miles would become popular starting in 1975. No one had yet thought to put on a race that was exactly 100 km.