Mr McNeill (54), of Invercargill, this week started his role as president of the national umbrella group for New Zealand tramping and mountaineering clubs, which represents more than 13,000 trampers and climbers.
He replaces Richard Davis, who stood down to work for the Department of Conservation (Doc).
He is also the editor of the Fiordland tramping guidebook Moir's Guide South and is known for rewriting Safety in the Mountains, launched last month.
Mr McNeill said he feared for the future of the back country.
Underfunding by Doc put back-country huts and tracks at risk.
"The great outdoors is part of every New Zealander's heritage and should not be disposed of through expediency.
"What remains of our natural environment is also under dire attack from predators, but the public has yet to grasp the urgency or scale of what is at stake."
A long-time member of the New Zealand Alpine Club and the Southland Tramping Club, Mr McNeill had also been on the Southland Conservation Board since 2003 and had taken a special interest in developing the Fiordland and Rakiura National Park plans.
He said the proposed Hollyford-Dart Tunnel and Snowden Forest Monorail projects "fly in the face of common sense", would "deface the natural landscape" and both projects "mock statutory plans".
"The process to date attacks the core of democracy," he said.
"And the public are waking up to what is at stake ...
"We have the most magnificent mountaineering opportunities to be found in the world and it's still there to be enjoyed.
"I want to ensure our grandchildren will be able to enjoy the same beauty and the wild of our unique natural heritage as my generation of trampers," Mr McNeill said.
