www.guardian.co.uk One of the world's classic mountain trekking routes is at risk of obliteration from plans to bring golf and skiing package tourism to the Himalayas.

Tourism chiefs in Nepal are keen to replace the stereotypical "trekker on a shoestring" with credit-card tourists seeking adventure holidays, including activities such as heli-skiing and paragliding.

The development will mean that the Annapurna circuit, which opened to backpackers in 1977, will be overwhelmed by a new road running through the heart of the Himalayas. Buses, taxis, motorbikes and tractors will ply the route connecting the mountain resort of Manang - currently reachable by footpath or air - to Nepal's national transport network.

Wildlife and plants will be destroyed and scores of porters and guides could lose their livelihoods, officials concede.

Aditya Baral, Nepal's senior foreign affairs adviser, said: "After the construction of the road ... the number of trekkers will be reduced. We have a trade-off here between economic development and infrastructure and the effect on tourism and the environment. We need to create alternative attractions to just trekking."

Baral, a former public relations director at the Nepal tourism board, added that Nepal wanted to attract different types of tourism. "We are trying to create man-made tourism attractions, like theme parks, adrenaline sports like bungee jumping and rafting."

At present, trekkers to the Annapurna region, in central Nepal, typically spend five days walking to Manang at 3,500 metres before continuing on for another two weeks to the resort of Pokhara. But the road is already being built along part of the route to Manang and eventually will follow much of the mountain trek.

Supporters say the plans are essential for the survival of Himalayan villages and for tourism in the area. But conservationists and trekkers have reacted angrily. The Annapurna Conservation Area Project group fears that tour operators will go to any lengths to increase profit from tourism. In a report, it said benefits from activities such as heli-skiing and golf "will mainly go to a few specialised tour operators and some more expensive hotels.

"Although there will be some trickle down [of profits], for the majority of the local people these activities will have little effect on alleviating poverty," it said.

Emmanuel Deghary, 29, from Marseille, who has made the trek four times, said of the new road: "There will be buses and tractors and lorries churning out their choking fumes all day and all night. Is this the way we want to treat our planet?"