" Marco Polo, who wrote that Mongol couriers could cover 250 or even 300 miles in a single day. Reading historical tales about such exploits, one could be forgiven for imagining the steppe as a single flat grassland through which horsemen moved with a sense of freedom and ease. Here on horseback, though, it was clear the cavalry were negotiating deserts, mountains, rivers, swamps, heat, and frosts, and somehow keeping their horses fed and healthy, even before leaving Mongolia. "

― Tim Cope , On the Trail of Genghis Khan: An Epic Journey Through the Land of the Nomads