As might be expected, the horse as well as rider traveled very light. The combined weight of the saddle, bridle and saddle bags did not exceed thirteen pounds. The saddle-bag used by the pony rider for carrying mail was called a mochila; it had openings in the center so it would fit snugly over the horn and tree of the saddle and yet be removable without delay. The mochila had four pockets called cantinas in each of its corners one in front and one behind each of the rider's legs. These cantinas held the mail. All were kept carefully locked and three were opened en route only at military posts--Forts Kearney, Laramie, Bridger, Churchill and at Salt Lake City. The fourth pocket was for the local or way mail-stations. Each local station-keeper had a key and could open it when necessary. It held a time-card on which a record of the arrival and departure at the various stations where it was opened, was kept. Only one mochila was used on a trip; it was transferred by the rider from one horse to another until the destination was reached. Letters were wrapped in oil silk to protect them from moisture, either from stormy weather, fording streams, or perspiring animals. While a mail of twenty pounds might be carried, the average weight did not exceed fifteen pounds. The postal charges were at first, five dollars for each half-ounce letter, but this rate was afterward reduced by the Post Office Department to one dollar for each half ounce. At this figure it remained as long as the line was in business. In addition to this rate, a regulation government envelope costing ten cents, had to be purchased. Patrons generally made use of a specially light tissue paper for their correspondence. The large newspapers of New York, Boston, Chicago, St. Louis, and San Francisco were among the best customers of the service. Some of the Eastern dailies even kept special correspondents at St. Joseph to receive and telegraph to the home office news from the West as soon as it arrived. On account of the enormous postage rates these newspapers would print special editions of Civil War news on the thinnest of paper to avoid all possible mailing bulk.