Keeping and eye out for bears - but bravig the chipmunks - Mark Aspinwall finds there's more to California than urban sprawl

I DESCENDED from the dusty Tehachapi Hills onto the brown floor of the San Joaquin valley, and engaged the cruise control for the first time. Los Angeles disappeared behind me at a constant 69mph. Route 99 stretched into the hazy distance in Roman straightness. Two or three more hours of monotonous driving and I'd be there.

I was heading for the King's Canyon National Park in the Sierra Nevada mountains for a couple of days of hiking with my brother Brian. The LA traffic had disappeared, and this artery of central California would not thicken with traffic until Bakersfield, an hour or so down the road.

The scene around me was reminiscent of Mexico - a dry, untidy, disorganised landscape under a blazing hot sun and a pale blue bowl of a sky. Scrubby brush and brownish-green trees struggled for survival in the oven-like atmosphere. Latin music blared from the radio, a cacophony of accordions, trumpets, and crooners.

But this wasn't Mexico. Roadside messages proclaimed values of right-wing America. Some advertised the Kern Fairground Gun Show the following weekend (every so often someone pokes a gun out their car window and shoots another driver who has irritated them, and so I flinched when an overloaded trailer next to me on the highway blew out a tyre).

One sign said: "Demand deportation of illegal immigrants now. The job they steal could be yours." It seemed like God-fearing Republican country, but this is California and things are never as straightforward as they seem. A little further down the road I saw a sign sponsored by the powerful anti-tobacco lobby. It said: "Tobacco is legal, profitable, and kills. Two out of three isn't bad."

California is perhaps the most polarised society in the developed world. For every stereotype there is an equally-true reverse stereotype. The state pursues a relentlessly avant garde set of policies forbidding smoking in public buildings, requiring recycling, and encouraging litter clean-up, at the same time as it harasses illegal immigrants.

In touchy-feely Santa Monica, next to LA, there is a policy permitting the homeless to sleep on the beaches, which LA itself forbids.

The highway signs were typical of the "in-your-face" approach to politics here, but the most striking thing about the San Joaquin Valley is not the signs but the geography: it is a desert fruit factory. Mile after mile of irrigated fruit trees lined the highway. I thought of Jack Nicholson driving through orchards in the film Chinatown. Water politics is still a touchy subject here, and the California Farm Water Coalition had taken to putting up its own signs: "Food grows where water flows".

Energy is now a touchy subject too - frequent radio service announcements advise energy conservation. Meanwhile, the gleaming big rigs and SUVs churn out CO2, because, unlike electricity, there is still plenty of petrol.

Mid-afternoon brought an ear-popping, temperature-dropping climb to over 6,000ft into the Sequoia National Park, next to King's Canyon. We were about 50 miles east of Fresno, among some of the biggest and oldest trees on earth. It was tempting just to park and tread the paths snaking around (and sometimes through) these arboreal beasts. But we still had supplies to buy, and, after a brief look we pushed further and arrived in deepest King's Canyon in time to see the day fade to dusk.

Next morning, we found the park ranger, who issues hiking permits and warns of the dangers of the area. And there were many. Bears, bad water, and forest fires, to name a few. We had to rent a bear can for $3, as insurance against a bear taking our food.

"If you see a bear, make it a real uncomfortable experience for him," the ranger counselled. "Throw rocks and yell at him, that's what I do. We need to let them know they are not welcome in campsites."

This contradicted my graven impression that, if a bear came your way, it was best to lie down (or faint) and pretend to be dead. "Not with black bears," he assured me.

The next rule is that campfires are a strict no-no except in designated campsites because of the danger of forest fires. And used toilet paper: it must be burned or taken away. This seemed to contradict the fire hazard rule, but the "no impact" rule is very rigidly adhered to. Human waste must be buried six inches deep and no paper left behind, so to speak.

'What about the gnats", I asked, waving a hand in front of my face. He laughed: "Yeah, they go for your eyes, nose, ears, mouth." I knew this already, having been outside the car for several minutes. "They don't bite though. Just go for a swim when you get up there and they'll be fine."

We set out for the upper section of Paradise Valley, a five-mile stretch of the Rae Lakes Loop. The loop is a five-day circular tour including a small section of the Pacific Crest Trail, which extends north to Yosemite and south past Mount Whitney, the highest peak in the lower 48 states, and contains some of the most beautiful scenery in the US.

The sky was cobalt blue, the air so dry it seemed to suck the moisture right out of our bodies. The trail was dusty, the air smelled of dry pine, and we strolled beneath canopies of sequoia, beech, and spruce. Lizards with blue stomachs skittered across the rocks. We spotted a rattlesnake, curled under a tree, and gave him a wide berth.

Granite walls soared 2,000ft above us on either side. They were etched and lined, like finely wrinkled faces, and grizzled with outcroppings of scrubby pine. The south fork of the King's River flowed past us. We only saw about 12 people all day, but they contained a high proportion of eccentrics. One man had a boot on one foot and a trainer on the other. Another read aloud from Hornblower as he walked with his family.

Twice we stripped and plunged into pale green pools of bracing, crystal clear river water. And the ranger was right, the gnats had disappeared. Finally, nine miles and about six hours after starting, we reached Arrow Creek in Upper Paradise Valley. We set up camp in a pine grove beside this burbling brook at just under 7,000ft, and lay down to rest our weary limbs.

Our limbs were weary because of the amount of water we had carried. We had no water purification except a cooking stove, so when we set out we were carrying seven litres of water and one of wine. Giardia is a debilitating disease spread by animal waste and very easy to get in isolated streams. Yet hikers must drink water constantly. It is like being on a raft at sea: water, water everywhere and not a drop to drink.

The gnats disappeared with the breeze and the cool of late afternoon. We cooked spaghetti on the stove, then lit a campfire and drew up around it with cups of wine. The campfire may not have been strictly permitted, but we had soaked the ground around it with water and doused it later with water.

Brian and I talked for hours. He was planning to get married, he said, "pretty soon". Meanwhile, the night drew in, the temperature dropped quickly, and the wine ran out even more quickly. So all the food was packed in the bear can and set upon a rock, with a tube of toothpaste left out as bait.

The tent was in the car (it very rarely rains this time of year) and so we felt slightly vulnerable at bedtime. Yet morning found us unmauled. There was no sign of bear intrusion, and though a small chipmunk danced along the river shore, he did not seem to pose a threat.

"Another sunny day in Paradise Valley," Brian reflected as we rose at 7.30am. The sun was still on the high peaks, and down here in the valley it was cold, perhaps under ten degrees. Breakfast was bagels and oranges. We made real coffee by using paper towels as filters. The coffee was very strong and... hey, toilet paper does burn.

For two days, Brian and I were in the face of the mountains, then we parted ways. Feeling a little blue, I pulled back on to Route 99, and headed for San Francisco. Resting in my hotel room, the phone rang. It was Brian. He had just arrived back in LA. "Mary and I have decided to get married Monday," he said. "I want you to be a witness. I have changed your flights around, I really appreciate it."