Of the eighty riders usually in the service, half were always riding in either direction, East and West. The average "run" was seventy-five miles, the men going and coming over their respective divisions on each succeeding day. Yet there were many exceptions to this rule, as will be shown later. At the outset, although facilities for shorter relays had been provided, it was planned to run each horse twenty-five miles with an average of three horses to the rider; but it was soon found that a horse could rarely continue at a maximum speed for so great a distance. Consequently, it soon became the practice to change mounts every ten or twelve miles or as nearly that as possible. The exact distance was governed largely by the nature of the country. While this shortening of the relay necessitated transferring the mochila many more times on each trip, it greatly facilitated the schedule; for it was at once seen that the average horse or pony in the Express service could be crowded to the limit of its speed over the reduced distance. One of the station-keeper's most important duties was to have a fresh horse saddled and bridled a half hour before the Express was due. Only two minutes time was allowed for changing mounts. The rider's approach was watched for with keen anxiety. By daylight he could generally be seen in a cloud of dust, if in the desert or prairie regions. If in the mountains, the clear air made it possible for the station men to detect his approach a long way off, provided there were no obstructions to hide the view. At night the rider would make his presence known by a few lusty whoops. Dashing up to the station, no time was wasted. The courier would already have loosed his mochila, which he tossed ahead for the keeper to adjust on the fresh horse, before dismounting. A sudden reining up of his foam-covered steed, and "All's well along the road, Hank!" to the station boss, and he was again mounted and gone, usually fifteen seconds after his arrival. Nor was there any longer delay when a fresh rider took up the "run."