Our friends had camped in the Parc National des Pyrénées (one donkey can easily carry a tent, cooking utensils, food supplies, and sleeping bags for two). That form of travel, though, deprives you of one of the great delights of being in France: French cuisine. So instead, Nicole carefully mapped out a route that took us each evening to a different farm or chateau, where, after parking Cabeilh in a pasture, we dined like d'Artagnan and his swashbuckling companions, slept in eighteenth-century castles, and, on one occasion, relaxed our tired muscles in a hot tub.

On our first hike we were joined by our former au pair, Antoine. He now works for Air France as a steward. Though not a pilot, he would still be the best navigator of our group (possibly excluding Cabeilh), I figured, so I gave Antoine the map. Besides, he reminded us, "I worked for Pizza Hut in Paris. I delivered pizzas on a bicycle."

Antoine looks like the young French cartoon character Tintin: He has a round face, a wisp of blond hair, and a surprising capacity for getting into—and out of—trouble.

We were soon lost. I think Cabeilh was the first to know, as she slowed her pace and tried to pull us through a hedge. We realized our predicament only when we reached a paved street that was not supposed to be there.

Getting lost on the GR is neither uncommon nor terribly serious. You simply retrace your steps until you find the elusive colored marking that you missed the first time. Our trail had turned off the dirt road onto a footpath with a barbed wire fence on one side and elephant-eye-high corn on the other.

As we tramped along the GR, we passed large tan dairy cows whose eyes followed us warily. Cabeilh would ignore them, as well as the occasional motorcycle, corn thresher, or irrigation geyser. Cabeilh was unflappable. Unlike the rest of us, she was unperturbed by the barking dogs that guarded every house we passed, whether it was a château or a rusted trailer. The dogs would come charging down the driveway and then stop, respectfully, about ten yards from Cabeilh. The strength of donkeys is legendary—certainly the dogs we passed had all gotten the word. But so is their gentleness. Jean Louis said that in 15 years of working with them, no donkey had ever kicked or bitten him.

Along the trail, Cabeilh would occasionally steal an ear of corn. She would munch on it happily, her powerful jaws crunching right through stalk, husk, and cob. Every time we stopped, she would immediately begin to consume the most accessible grass, weeds, leaves, thorns, and tree branches. Another advantage of traveling with donkeys: You do not have to pack them a lunch. They forage for all their own food.

Donkeys are also very sociable. Instead of wandering off when untethered, Cabeilh would wander over to us. She liked being brushed and having her long ears scratched, and she seemed to enjoy our company. Whenever our friends had spread out their map and gathered around it to find the route, their donkey would stick its head into the circle and study the map with them.