Elser has written the names and dates of death of many of his mules and horses on a wall in his office. His pack animals often serve for more than 20 years, and can live 40. TOM BAUER/Missoulian ...

Ruth passed in 2002. Not long ago, he saw a news report about the war in Afghanistan. The Army had brought back mules to carry supplies in the country's rugged terrain. The Mule Pack lives on.

Mules and donkeys can carry food, water, weapons and other heavy or bulky items, Glenn said. Without the pack animals, the soldiers would have to carry the gear.

Sierras by saddleThe details On the all-inclusive trips, the mules carry up to 30 pounds per person. Outfitter provides horses, food, drinks, cooking equipment, dishes, lanterns, portable toilet ...

Garbage bags fill up. But the mule saddles always have to ride even. “We pack rocks all the time,” Burns said. “You need them to balance the load. “It really screws up the geologists.