Dragon Overland Movement
True dragons are exceedingly strong flyers and can cover vast distances quickly. A dragon’s overland flying speed is a function of its normal fly speed, as shown on the table below.
Dragon Overland Flying Speed
Dragons do not tire as quickly as other creatures when moving overland on the ground. If a dragon attempts a hustle or a forced march, check for nonlethal damage once every 2 hours instead of every hour.From from d20srd.org.