Two track extensions opened in Thredbo this month to become part of a spectacular 35-kilometre route from the village to the valley. The 900-metre descent covers diverse terrain from spectacular alpine areas scattered with rock boulders, to luscious greenery and water features.

Thredbo Mountain Bike's assistant manager Tim Windshuttle said completing the longest purpose-built mountain bike descent in the country was a milestone that would greatly benefit the region.

"You do have long descents in the country, but nothing mountain-bike specific of this length," Mr Windshuttle said.

"This will be a huge boost. The sport is already booming in the area and I think this will be a drawcard for everyone, not just from Australia but internationally."

The new route consists of the Thredbo All Mountain Trail and the Thredbo Valley Track.

When Thredbo launched the Thredbo All Mountain Trail in November, the village saw a 50 per cent jump in visitation. For the first time riders could follow the 17-kilometre path over Skitube Bridge to Friday Flat.

The NSW National Parks and Wildlife Service opened the Thredbo Valley Track in 2015. The new six-kilometre section starts at Friday Flat and runs through a remote part of Thredbo River. It will be the first of several extensions of the track.

The masterplan is for the joint trail to form an incredible 60-kilometre route from the top of Thredbo all the way to Lake Jindabyne.

Thredbo Valley Track project manager Chris Darlington said he aimed for the project to be complete in two years, but it could take longer due to the challenges of constructing in an alpine environment. The amount of track built in one day could vary from five to 100 metres, he said. Transporting gravel for just six kilometres of the track required 100 helicopter rides from Bullocks Flat.

But he said transforming the Snowy Mountains into a world-class mountain biking destination was worth the multi-million-dollar investment.

"When we first opened the Thredbo Valley Track, you could see more and more vehicles rolling in with bikes, and everyone - from bike shops, accommodation, resorts, restaurants - were all talking about the buzz from mountain bike riding," he said.

"Some people only come up here during winter and that will always be the case. But we're seeing more people wanting to come up here all year 'round as this sport grows."

Mountain-bike riding is recognised as an adventure sport, but Jay Williams from Lake Crackenback Resort said a growing number of families were hitting the tracks.

"Unlike weekend sports for kids, the whole family can create special memories together in special places," he said.

"Both families and pro-riders can now come here and ride for a whole week without doing the same track twice, which is pretty impressive."

With this in mind, some parts of the Thredbo Valley Track were more family-friendly than others. Outside sections were wider and flatter, for beginners to easily ride or walk, but Mr Darlington warned families not to tackle the entire route without some off-road biking experience and adequate preparation. He said they must be physically fit and self-sufficient in an emergency.

The Thredbo All Mountain Trail was also an intermediate ride. However, Thredbo communications manager Susie Diver hoped that would not discourage first-timers from trying out the sport.

"I started riding four years ago to share the passion with my daughters, and I would get anxious when I knew I had to go down the mountain," she said.

"But now I get excited every time."

"Being out here in the great outdoors, with 360-degree views of the most spectacular alpine terrain you'll ever see, is really quite enviable."