Most of the road signs had bullet holes in them. Behind me, in the toy-box town of Carefree, the United States stopped pretending to be something cosy. From here on, the ancient silence of the Wild West held sway.

I had hitched a ride from town and was dropped where the reassuring tarmac turned into desert dirt track. My ride disappeared dreamily back into the mirage of an empty highway. Ahead, among the bullet holes, I read “unsuitable for motor vehicles”.

Somewhere out there was a Yorkshireman. In a cabin by a creek in the Arizona desert lives the writer and eco-warrior Geoffrey Platts. Although his precise address is a secret, I had persuaded him to give me the details and was on my way to see him.

The map in Geoffrey’s letter had been intricate, and after three hours’ walk, I slipped down the rocky bank of the creek and there was the cabin. It was on the other side of the stream, nestling between leafy sycamores, cottonwoods and evergreens. How come there were so many trees down here? Just minutes earlier, I had baked in searing Kodak blueness amid hot rocks and giant cacti.

“This kind of habitat is called Riparian,” Geoffrey explained. “It’s very precious. The water rises from a spring a mile upstream and dries up two miles downstream. In between is an oasis packed with wildlife.” Little did I know how right he was. That night my tent was surrounded by a munching herd of Javelina which peered haughtily into the torchlight I shone from behind the screen netting. “They’re not aggressors, but they’ll rip a dog apart if it attacks them,” Geoffrey remarked.

He regards his cabin as a fortress from which he wages war on what he calls “dollar-crazed developers”, a sub-species of the race Homo rapiens. Carefree town had smelled of money. The last housing development I had passed on my way out had an 18 hole golf course on one side and a private airstrip, complete with private hangars, on the other.

The real-estate developers know who Geoffrey Platts is. He capaigns against every Nature-crunching project he hears of, and is a thorn in the flesh of wealthy “landscrapers”. All this in a state where it is legal to carry a gun, and where capriciously sprayed bullet holes attest to people’s impatience to use them.

“I tend to think more and more like an Apache,” said Geoffrey, as we set out the next morning on a four-day survival hike. “This area is only classified as desert because it gets less than ten inches of rainfall a year, but when those rains come in the Spring the whole place explodes with wild flowers.”

The Sonoran Desert in that part of Arizona is indeed spectacular. Mountains and flat-topped mesas rise out of a vast, bushy desert floor. Reaching gaping-tall into flawlessly blue skies that really stretch the eyes, they flaunt the individual shapes and identities that gave them their names, such as Skull Mesa and Camelback Mountain. Stands of giant Saguaro Cacti stake their ancient claims, like petrified armies, on the south-facing mountain slopes. Many are two hundred years old and as tall as a house. Raccoons, rattlesnakes and lizards, rare mountain lions and birds of prey grace the uncanny silence.

Now and again, Geoffrey would point out evidence of a more alarming species, the Weekend Warrior. “They’re a strange breed of hunter: city people who get so frustrated with their frantic existence that they drive out to the desert at the weekend armed to the teeth. They shoot at anything: deer, birds, telegraph poles, each other. They rarely succeed in hitting anything and never stray more than ten paces from their four-wheel drives. What gets me is they disturb the tranquillity of the desert and always leave a trail of beer cans behind them.”

Geoffrey then told me of an incident the previous year in which a drunk Weekend Warrior had opened up with a sub-machine gun on a Saguaro cactus. The 150-year-old monster was rotten, however, and fell on top of him, impaling him on the spot. The Yorkshireman’s wink said it all. For him, this desert is alive.