Costing 3.76 billion yuan (450 million US dollars) and covering mountainous areas more than 3,000 meters above sea level, the highway network is expected to connect the Tibetan Autonomous Prefectures of Aba and Garze and the Yi Autonomous Prefecture of Liangshan by the end of next year, the highway builders said.

So far, more than 15 million square meters of road surface havebeen paved since the project kicked off in June last year.

Calling it an important measure the Chinese government has taken to develop the vast western region and to speed up economic development in ethnic areas, Huang Zhendong, former minister of communication, said most of the funds for the project would come from the central revenue.

Located in the western part of the Sichuan Basin, the three ethnic autonomous prefectures cover a total land space of 300,000 square kilometers, or 60 percent of Sichuan's total. Inhabited by more than 5.6 million people of the Tibetan, Qiang and Yi ethnic groups, the area is also rich in water and mineral resources.

For a long period of time, local rich water, mineral and tourism resources were not developed and exploited due to bad geographical conditions and poor communication facilities.

A farmer from Liangshan Prefecture said his hometown is rich inapples and but that did not bring any benefit to local people.

"Only a small portion were transported to other parts of China and many became rotten," said the farmer.

At present, the total length of highways is only 21,000 kilometers in the area, or 7.1 kilometers per 100 square kilometers.

Zou Guangyan, deputy governor of Sichuan, said this project was expected to play a key role in promoting the development of tourism, the power industry, farming and animal husbandry, energy-consuming and special industries in the area.

Most significantly, he noted, the project is expected to ease the threat to the environment of the Yangtze River brought about by local people.

Zou said for several decades, people in the area relied on felling primitive forest to make ends meet, bringing serious damage to the environment along the upper reaches of the Yangtze, the longest river in China.

The three ethnic autonomous prefectures carry many tributaries of the Yangtze and are dubbed the "lung" of the river.

To protect the local environment, felling of primitive forest was banned in 1998, and local people were urged to plant trees andgrass on sloped farmland instead of growing crops.

The highway network would bring about exchanges of information and commodities between the project area and the rest of the country, said Xing Jinrong, an official with Sichuan Provincial Communication Bureau.

The local tourism industry, in particular, is expected to become a big beneficiary. Thanks to the construction of the highway network, Aba Prefecture alone received more than 2.4 million visitors last year.