Only in California would Sarah Shuckburgh find, among warm people and spectacular scenery, a volcano with mystical and magical powers.

The inhabitants of Dunsmuir, in California’s far north, reckon that their city is the best place in the world to live, and it is hard to disagree - although ‘city’ seems the wrong word for a friendly place with only 2000 people, no traffic lights, no parking meters, and scarcely any cars.

At the Cornerstone bakery each morning, my husband and I tuck into fried eggs over-easy and smoky applewood bacon, with sides of hash browns and spinach, sourdough toast and warm harvest muffins. Coffee comes with glasses of delicious water, which locals say is the purest and healthiest in the world. From the high ceiling, with its 1920s plasterwork, fans turn slowly. It is the start of another perfect day.

The narrow straggle of Dunsmuir nestles in a steep-sided, forested valley beneath a hot blue sky - but the peace is punctuated by the hoots and rasping screeches of clanking goods trains. This is a historic railway town - founded in 1887 during the boom years of the Central Pacific Railroad Company. Originally known as Pusher, after the engines which shunted logging trains through the steep canyon, the town’s heyday came in the 1920s, when 2000 men worked on the railway, and Babe Ruth came to play on the city ballpark.

Today, motorists who turn off Interstate 5 find a town where the best of the olden days has survived, and the pace of life is slow. Children bathe in swimming holes in the glassily clear Upper Sacramento river. Wide streets are lined with whitewashed shingled houses, many over 80 years old, their verandahs decked with flowers. Drivers stop to let pedestrians cross the road, and everyone inquires how you’re doin’.

We are staying in Pam’s Place, a delightfully cluttered clapboard house built in 1901. Pam insists that we start by visiting Dunsmuir’s two famous waterfalls. She boasts that George Bush Senior visited Mossbrae Falls just two weeks ago - and the only way there, even for an ex-President, is a hot, half-hour walk along the narrow railway track.

Listening anxiously for sounds of a train above the roar of the Upper Sac rapids, we hop between concrete sleepers, and skid on heaps of sharp pink-grey chippings. Suddenly, we hear a thrilling hoot, and the rails begin to rattle and hum. We lean back on the chippings as a massive locomotive thunders slowly into view. An arm waves from the cabin, 20 feet up, and the engine rumbles by, pulling 80 rattling goods carriages, laden with redwood trunks, boxes and barrels beneath flapping canvas covers. At last the deafening procession passes, and there is silence apart from the gushing river.

The Mossbrae Falls are worth the risky walk. Pristine water, underground for 500 years, erupts across a wide stretch of the canyon side in a thunderous, glittering curtain, tumbling through moss and other greenery, and sending up a cloud of cool spray. I have a brief, icy dip in the deep pool beneath the falls, before we brave the railway track again.

Back in Dunsmuir, we follow a safer, sun-dappled path down through mixed woodland and poison oak to the town’s other waterfall, a narrow cascade pouring noisily out of a cranny on to boulders and fallen tree trunks. Behind Hedge Creek Falls is a muddy cave where Black Bart, local stagecoach robber and bandit, used to hide from the posse.

Beyond the town is some of California’s most beautiful back-country, a vast, sparsely-populated wilderness of forests, white-water rivers, clear blue lakes, misty waterfalls and granite crags. And presiding over this extraordinary landscape is Mount Shasta, north America’s highest volcano - snow-capped even in midsummer, with an awesome beauty, and, many say, mystic and magical powers.

Native Americans had worshipped the great white mountain for centuries before settlers arrived with a new range of supernatural beliefs. The 1920s and 1930s were peak years for sightings of cave-dwelling survivors from lost civilisations, and new-age visitors today still hope to meet Lemurians (seven feet tall, with a walnut-sized extra-sensory organ on their foreheads), Atlanteans (from the sunken continent of Atlantis, who live for 150 years eating only sunshine, moonshine and cosmic rays), or Yatavians (who excavate underground cities with bell-ringing vibrations). Spaceships have been seen refuelling as they hover in lens-shaped clouds over the peak, and unknown beings have left tiny foot-prints and giant foot-prints, mystic stone circles, and, beneath the mountain, hundreds of miles of tunnels lined with gold and liquid sunshine - but with entrances impossible to trace.

Pam is sceptical about the spaceships, but she’s sure that the pure air of the sacred mountain prevents sin and corruption, and ensures bodily and spiritual well-being in Dunsmuir, just six miles away. We drive up a winding road beyond the tree-line, to cool alpine meadows and stark slopes of scree covered in deep drifts of snow. Here, at 8000 feet, the views are breathtaking. Above us, another 6000 feet of dazzlingly white snow soars to meet an impossibly blue sky. All round us, undulating forests stretch to infinity, pierced by smaller volcanic peaks and by rocky Castle Crags, a rugged array of spires and pinnacles of ancient granite. The astonishing vista makes me feel elated and giddy. Or have I been touched by converging rays of cosmic power?

The town of Mount Shasta, at the foot of the mountain, has bookshops stacked with literature on the mountain’s spiritual energy vortex. I pick up a newspaper - the Mountain Spirit Chronicles - and read articles on higher consciousness channelled from Gaia and St Germain into local laptops. St Germain, an Ascended Master, has helpfully revealed a range of age-defying cosmetics, now on sale in pharmacies and online.

As the afternoon cools, we return to Dunsmuir’s grandly-named City Park - a lovely stretch of old-growth forest, with sandy footpaths along the steep banks of the Upper Sac, which provides some of the best wild trout fishing in the world. We sit under a tree, watching fly fishermen, knee-deep in the sparkling water, casting their lines. Hummingbirds and butterflies flit among flowering shrubs in a small botanical garden, as another goods train rattles by on the far bank.

Next day, we drive north through empty Siskiyou county, and emerge from the forest at the Lava Beds National Monument, a grey and black wilderness strewn with sage brush and juniper scrub, dry, hot and inhospitable - but inhabited by Native Americans for more than 11,000 years. The terrain looks like a moonscape, and indeed the original Apollo astronauts practised lunar-landing here. The monument recalls a fierce battle in 1872, when a few dozen Modoc Indians held off 600 American soldiers, killing their general. Eventually, the Modocs were beaten. Most were executed, but some were moved to reservations, and we meet modern-day Modocs from Oklahoma and Oregon, here for a reunion in their tribal homeland. Watching for mountain lions and rattlesnakes, we walk, through blistering heat, to see ancient wall-paintings, before clambering down to the welcome chill of strange lava-tube caves.

The nearby Lower Klamath Reserve is a high-altitude desert surrounded by a ring of grey mountains. Here, wetlands are carefully maintained for bird-watching, and also - surprisingly - for shooting. As we bump along dirt tracks between lagoons, thousands of white pelicans take to the air, with graceful egrets, white-faced ibis, American avocets, Western grebes, red-winged blackbirds. Ducks swim through the reeds with processions of ducklings. We also spot bald eagles, more common here in winter when they fly south from Alaska. In early spring and autumn, millions of birds migrate along this Pacific flyway.

Driving back to Dunsmuir we stop often, staring in disbelief at the endless sweeps of dark green forest, which fade with distance to pale, hazy grey. But our gaze is always drawn to majestic Mount Shasta, a snowy triangle radiating joy in the evening sunshine - the largest lone peak in the world, and surely the most beautiful and benevolent.

First published by the Telegraph
©SarahShuckburgh