Zhaqu River, in the upper reaches of the Lancang River in Niandu village, Angsai town, in the Yushu Tibetan autonomous prefecture in Qinghai province.[Photo by Yang Yang/China Daily]

Niandu Village, near where we had our puncture, is one of the 53 villages in the national park.

We were at about 4,000 meters above sea level. Although I could not move fast, I felt much better than two days earlier, when we ascended from Xining, at 2,300m to the Yellow River-Source region of Maduo county 4,300m where I had spent a sleepless night, suffering from a bad headache caused by oxygen deprivation.

We were now in an open valley. The Zhaqu River, an important upper branch of the Lancang, wound through the mountains afar. There were few trees other than cypresses in sight. Grass carpets that had turned yellow in late September extended onto the low mild slopes of the mountains. It was a splendid view.

Before long, chunks of dark cloud pressed down above us and it started to rain. A gust of wind blew, the air become more chilly and it rained more heavily. Luckily we got to the car in time. As we jumped into it, and before I could roll down the window thunder boomed and hailstones blasted the car, hitting the roof like bullets.

For me, this sudden change of weather was exhilarating. The hail soon stopped but the rain continued. A mountain road that at first had been merely difficult soon became dangerously muddy. The Land Cruiser drivers cautiously eased their vehicles down the continuous 60-degree grade roads punctuated by hairpin bends.