The above photo is from johnsigrid.blogspot.com. It is a photo of an actual Pony Express mochila that John and Sigrid saw at the Pony Express Museum in St. Joseph, Missouri.

Before I explain the mochila, I want you to know that the Pony Express began it’s run in early April 1860, and the Pony Express plays a big part in my upcoming novel.

Mochila is the Spanish word for knapsack or pack, and this particular type of mochila was used by the Pony Express. It fit over the saddle, as you can see in the above photo, it had four pockets or cantinas–two on each side.

Mail would be placed in three of the pockets and they would then be locked. There were only two keys for the locks, and the two keys were at opposite ends of the trail–one in St. Joseph, Missouri and the other in Sacramento, California.

The fourth pocket of the mochila was left unlocked and empty in the event that the Pony Express rider would receive a military dispatch along the way.

Mail was written on onion skin paper and was wrapped in oil cloth to protect it from the weather.

The Pony Express charged $5 per half-ounce for mail, which is about $85 in today’s money. They later reduced it to $1.

Because they needed to take care of the horses they rode on the route, there were weight restrictions for horse, rider, mail, and equipment. The maximum weight of the horse was 165 pounds. A rider had to weigh less than 120 pounds because they carried twenty pounds of mail and twenty-five pounds of equipment.