As dawn broke on the western plateau in Sichuan province, Sanga and his family began to milk yaks that had been roaming in an alpine meadow.

Before the blazing sun hit its peak at noon, the herder, in his 50s, had returned home in his van with nearly 300 yuan ($42) after selling 20 liters of fresh yak milk in Nandamu township 30 kilometers away.

Two years ago, it would have taken him the entire day to make the round trip and the yak milk would have fetched less money.

Sanga lives in Wukeji village, Shangduke township, in Zamtang county of the Aba Tibetan and Qiang autonomous prefecture. Nandamu township is the nearest and most important market town for the herders.

Shangduke is set in alpine meadows, while Nandamu is located at the foot of a mountain. For years, the only access between the two townships was via a narrow meandering path.

When the herders wanted to sell their yak milk, meat and butter, they had to travel on horseback along a mountain trail, or make a 70 km detour traveling on an asphalt road through Zamtang county.

"It took me five to six hours ride by horse to reach the town to sell milk. The price was 4 yuan for a half liter," said Sanga, who goes by only one name.

"Cheap prices were offered to us because the buyers knew that we had come a long way and if we didn't sell the milk, we wouldn't find any other buyers in time. The milk could go off and we might not make anything."

In October and September, the herders also drove yaks down the mountain to sell at market, which was a day's journey, Sanga said. Money had to be spent on accommodation and fodder if the herders had to wait for buyers, he said.