Question:  Lisa Smith-Batchen was the first American to win  Marathon des Sables a six day marathon that spans how long of a distance?
Sentence (from "Marathon des Sables"): Marathon des Sables, or MdS, (French for Marathon of the Sands, also known as Sahara Marathon) is a six-day, 251 km ultramarathon, which is approximately the distance of six regular marathons.
Relevant evidence: Yes