When Bonnie was about eighteen months old, I was out with my family at a Christmas tree lot, when a man approached us to ask us about Luke, our corgi. “Do they make good house dogs?” he wanted to know. Oh yes, we all assured him. They're great little house dogs. Then he wanted to know what kind of a mix our other dog was. When I told him she was a 100% pure working-bred Australian Shepherd, he asked if that kind of dog made a good house pet too. Before I could open my mouth, my whole family chorused “NO!”

I had to admit she wasn't exactly ideal. At that time she was still eating the tassels off knit hats and thought pencils were dog treats. She picked up annoying habits with astonishing rapidity, teased the cat without let-up, and had learned how to open the dogfood closet door, something generations of corgis hadn't figured out. My family did not appreciate her gifts.

The summer Bonnie turned two, we went on a backpacking trip in the high Sierra. The Sierra backcountry is vast and, where we were, nearly empty of human beings. It isn't called the high Sierra for nothing either—we were mostly above nine thousand feet. Since we normally live at the ocean, we all, at one time or another during the trip, suffered from altitude sickness (except Bonnie, who throve). My own bout took place about four days out, hiking across a tilted sheet of granite in blazing sun. This little piece of rock was at least twenty acres in extent, and when we had crossed it previously, we had carefully followed the small cairns or ducks, stacked rocks which marked the otherwise invisible trail. But somehow on the return journey, we lost them.

While the others tried to find the cairns among all the scattered stones, I leaned in the shade of an enormous boulder and felt dizzy and weird. Bonnie happily accompanied the searchers, coming back to check on me periodically. An hour passed, and no one could find anything more than deer trails. Finally I said weakly, “Bonnie, let's go home. Let's just go home.” I don't know exactly what was in my mind, but Bonnie at once leaped up, and trotted without the slightest deviation to the edge of the granite, in a direction no one had thought of, and stood looking back inquiringly. Of course, it was the trail back to camp.

And just recently I was taking my daily walk up to the ridge, when a family of feral pigs trotted across the fire road ahead of me. Bonnie raced up, and as they spooked and ran down hill into the forest, she cut the last piglet out and herded it, squealing and grunting, back down the road toward me. She was thoroughly enjoying herself but I was terrified the momma pig, huge, black as death and twice as ugly, was going to miss her youngster and emerge from the underbrush with a real bad attitude. I yelled at Bonnie to quit and she finally did, not without obvious regret.

These little anecdotes are only to say, what goes into making a useful herding dog is complex and subtle. Bonnie is the brightest dog I've ever had, but more than that, she is precise, indefatigable, intensely curious, endlessly persistent, and constantly poised to be helpful. And, she will try to herd anything with legs, apparently. But I hate to think what she would be like if her life consisted of a daily on-leash walk around the block, and five days a week left alone all day to do nothing, waiting for her family to come home from work and school. Even as it is, with a three mile off lead run every morning, and three to five hours a week of livestock work, she is a very underutilized dog.

In Jean Donaldson's priceless little book about dog training, Culture Clash, she points out that the vast majority of dog owners want their dogs to do almost nothing but be happy to see them when they come home. It is surprising, but a great many dogs succeed in the rather difficult task of doing hardly anything for their whole lives. But Bonnie wouldn't, and neither would most working dogs of any breed.

The sum total of her qualities is a hard thing to describe but now that I've experienced it, I know I'll always recognize it. The point is, she was born to do.