After that any changes would still have to be approved by the New Zealand Conservation Authority and Government ministers.
The new pieces of walking and cycling track are being sought by Ohakune 2000 and the Ruapehu District Council. They say they will relieve pressure on the Tongariro Alpine Crossing and Tongariro Northern Circuit by diverting visitors to the south.
They will provide opportunities on days when weather is not suitable for the northern walks, and make Ohakune a year-round visitor destination.
The 22km descent, called Te Ara Mangawhero, would be for both cyclists and walkers. It would remove them from the narrow Ohakune Mountain Road, making it safer and eliminating the need to widen it.
The park's Round the Mountain Track includes a 3.5km stretch of the Ohakune Mountain Rd. That piece would be walked on Te Ara Mangawhero instead.
A Conservation Department feasibility study estimates the additions could bring an extra 34,000 visits and $5.7 million a year to Ohakune, within five years.
It says Te Ara Mangawhero would have minimal environmental effect. Much of it would be on the existing Blyth Track, which would need to be upgraded.
Not everyone is full of enthusiasm. The Federated Mountain Clubs of New Zealand worry the new descent will attract so many cyclists that it will be unpleasant for walkers.
The track additions would cost nearly $5 million, and be funded and managed by a community group. Te Ara Mangawhero will get $320,000 from Ruapehu District Council and cost about $20,000 a year to maintain.
The Accelerate25 Action Plan has $2 million to contribute to the whole project. The work may be done in stages, with Te Ara Mangawhero first.
Another proposed addition is a new 11km track higher up Ruapehu that would make the Old Coach Road a loop track and take in some historic logging tramways.
The third piece links Horopito and National Park for cyclists and walkers. Much of it will be on the old Marton Sash and Door tramway, but 600m is inside the national park and needs the plan change to go ahead.