Quick AnswerThe Short Answer
Merzouga is about 470 km from Fes, roughly 7 to 8 hours of driving without stops. It is the shortest road to the Sahara from the north of Morocco, and a beautiful one: the road climbs through Ifrane and the cedar forests of the Middle Atlas, crosses the high plateau at Midelt and drops into the Ziz Valley, a long ribbon of palm groves leading to Erfoud and the dunes.
Most travellers do it in one full day with stops and arrive in Merzouga in time for a sunset camel ride and a night in a desert camp, then continue to Marrakech through the gorges.