In the first of three dispatches from China, Sara Wheeler treks from Yunnan to Sichuan.

The shadow of a black-necked crane crossed the fretted light beneath the arms of a Himalayan yew. That curious evanescence of air particular to the Tibetan plateau sparkled through a quiet Chinese dawn, and my horseman yelled out the old song of the mountains.

I was trekking from Yunnan into Sichuan, two provinces now officially Chinese but once integral parts of the kingdom of Tibet. On the western flanks, both abut the foothills of the Himalaya, and the tang of snow was never far off, even when the sun shone. This corner of China – not in itself small, but dwarfed by the magnitude of the nation – characterises a facet of the Middle Kingdom forgotten in the dizzying rush to modernise.

The journey began at Lake Lugu (Lugu Hu); specifically, at Lige on its northwestern shore. Stepping across rills of sand ringing the 52-square- kilometre lake, I hopped into one of the low rowboats called zhucao to reach Liwubi Island, where Mosuo people settled early in the sixteenth century. Today, the 40,000 Mosuo represent one of China’s 56 recognised ethnic minorities, and almost all of them farm close to Lake Lugu, the women conspicuous in the fields in day-glo pink headgear. Short, strong and flat-faced, Mosuo closely resemble ethnic Tibetans, with whom they have a close kinship. But unlike Tibetans, Mosuo are matrilineal – the last genuine matrilineal society on earth. They enjoy an unusual conjugal system, which is to say, they don’t have one. Women and men pair up by mutual consent in the female’s house for a night, or maybe a year, and when the arrangement breaks down the man returns to his mother’s home with no harm done. Offspring remain in maternal care, and the eldest woman in the family takes charge of the household. Han Chinese call the system ‘walking marriage’. At any rate, the women seemed to be doing all the work – I saw them every day, hauling teetering loads of hay on their backs or tugging buckets of water from the well.

Beyond Lige the landscape unfurled like a painted Ming scroll. Squares of sorghum and cabbage shrank beneath smoothly rounded, biomorphic mountains, clouds suspended like canopies half way up. Wooden homes occasionally punctuated the teal seas of the valleys, many flying white streamers from their curved eaves to honour ancestral reincarnation. A water buffalo picked out a delicate path. A 5.7-magnitude earthquake had struck the area three months before my visit and a pale blue tent donated by a Chinese NGO stood close to each home (in most cases the houses had not been destroyed – wood does better than concrete in a quake – but the regional government was still advising residents to sleep in tents in case of aftershocks). At the Zhamei Buddhist temple in Yongning, the monks were actually living in blue tents. At almost 3,000 metres Yongning enjoys a soft Himalayan climate, and at the temple prayer flags flapped lazily as breezes rustled the pipal trees. In the dim pavilions, flickering ghee lamps illuminated painted statues of Gemu, the Mosuo mother goddess. The gold-plated copper roof of the main pavilion had survived not just the quake but also the depredations of the Cultural Revolution (just), but much had not outlived that painful decade. Zhamei means ‘No War’ in Tibetan. It had turned out to be wishful thinking.

Wenquan was a small agglomeration of courtyard houses in an agricultural river valley lined with spiny hills, cornfields and mud-brick walls encircling vegetable gardens. The hillsides were dense with Himalayan poppies, azalea, alpine primulas and swathes of a delicate flower so blue it was vulgar. Around the hearth in the single simple guesthouse, my Mosuo host had painted the walls with bright images of fish, lotus and peacocks. Five-foot long cured pigskins were stacked on top of one another, their mouths and other orifices sewn, doing duty as a sofa before the last meat was devoured. In the mornings, I sat on them to drink butter tea served from an iron kettle.

While historically isolated from the rest of the country, that corner of Yunnan lies on the Tea Horse Road, the ancient trade route Chama Dao. Although not as famous as the Silk Road to the north, the Tea Horse Road was equally important in the tumultuous saga of Chinese history. Tibetans wanted Chinese tea and the Chinese imperial court wanted Tibetan horses, and for centuries caravans trekked along the same thin paths that I was following out of Lake Lugu and onwards to Sichuan.

Mosuo practice a tradition of easy hospitality, and often invited me in to their homes. At one end a monumental black sow always lived in a small room from which she exited and entered with decorum when she needed to use the facilities in the adjoining barn. Off the courtyard to the left, a matriarch Mosuo generally lounged in the bed of honour next to the fire. (Mosuo women seemed to be remarkably long-lived – I met one who was 96 and another 103.) Outside, spritely 70-year old-daughters sat among piles of spinach, chopping away with cleavers.

One morning I walked for three hours and met only a goatherd lying next to a fire with an antiquated rifle at his side. When it started to rain, he plucked a leaf and whistled, repeating the procedure over many minutes, one leaf per whistle, and eventually his 200 charges assembled, ambling in from every direction. At the next village a new stupa had recently been erected on a hill, and a festival had been declared for its filling and sealing, a sacred ritual in which Mosuo entomb written prayers, ancestral relics and assorted gifts for the spirits. Soon after dawn villagers began carting up plastic bags of hard-boiled eggs, apples, cured ham and bottles of fizzy pop. Shortly after eight, six lamas in wine-coloured robes and yellow sneakers started to incant, and the putting-in and cementing-up proceeded in good order for some hours, finishing off with a dozen rounds of firecrackers, vigorous blowing into conch shells, pyre-lighting and incense burning, all accompanied by laughing, shouting and shrieking as smiley lamas bustled round. At the end of the day, leftover food was divided into bags for visitors to take home. The last rays of the setting sun glittered on the rice fields and a deep peace settled over the crowd, conferring, or so it seemed to me, a sense of unending continuity with the landscape where Mosuo have lived for untold generations. As we straggled down the hill, the clouds burst, and rain drenched us.

The Mosuo have survived everything history has hurled at them, but the worst may be yet to come – the clouds gathering are metaphorical as well as meteorological. The Han continue to push west from the wealthy cities of the eastern seaboard. As I write, developers are moving cranes and dozers into those secluded valleys to build hydroelectric plants, and Yunnan’s forest cover has already halved. There is little outward sign of the environmental vandalism inflicted on China in this idyllic and isolated part of the country, but it is there: poisoning rivers, drying out lakes, polluting the thin air.

On the next leg of the journey the terrain was rough and the way uncertain, so I travelled with a packhorse and horseman. The latter, Gesang, was an affable, ink-haired Mosuo from Wenquan, and he had learned a little English working as a waiter in Lijiang. His robust pony had a short, neatly clipped mane, and the tinkling of bridle bells marked our passage. As soon as we entered deep forest, Gesang began collecting wild mushrooms, and the activity seemed to please him greatly; he sang loudly and chuckled to himself. At our lunch stop – he told me the spot was called Twenty Turns – we roasted the mushrooms on willow sticks and ate them with cold scrambled egg left over from breakfast, served from a plastic bag. Later that afternoon Gesang recognised a woman carding goats’ wool in a cleft of the valley. He stopped to talk with her while I lay among the wildflowers. The woman was minding a pig and 14 piglets. After their conversation, she and Gesang sat in silence for a long time, listening to the silence of the hills. I fell asleep, and a piglet woke me up, licking my face.

That night Gesang, the pony and I crossed into Sichuan and put up at Lijiazui, a straggly half-Mosuo, half-Mongol hamlet, ancestors of the latter having galloped in with Genghis Kahn in the thirteenth century. The streets were made of mud, and our accommodation enjoyed cardboard mattresses and no sanitation of any kind. Wires from a recently installed electricity system trailed nomadically from bare room to bare room, but no longer worked (had they ever, I wondered?) Yunnan is a poor province compared with booming Sichuan, but there in the quiet borderlands the difference did not exist and never had. Almost every Mosuo seems to know every other one, and that night Gesang’s cousin’s wife’s family, who lived in Lijiazui, invited us for dinner. I sat cross-legged round the hearth in the place of honour and ate grated potato, pork and pickled persimmon. At midnight, our host led us back to our spartan accommodation holding a flaming torch. Shanghai and its cranes seemed a long way off.

Read the second and third of Sara’s Chinese dispatches here and here.