Riverstone Holding Ltd wants to build the $150 million, 43km monorail from the Kiwi Burn entrance near Mavora Lakes to Te Anau Downs.
The Department of Conservation has indicated it will approve the concession, subject to public submissions.
All 19 submitters at the hearing, chaired by Graeme Ayres, opposed it.
Reasons for the opposition were destruction of ecological values, natural remoteness and solitude, and the adverse effects on recreational use of the area.
Hunter Glen Dean said the monorail would destroy pristine natural areas that were easily accessible but still felt completely remote.
"This is a wilderness area that's accessible to, in particular, locals, and this monorail concept is not something we want. I despise turning our conservation land into a theme park like Disneyland."
Venture Southland group manager enterprise and strategic projects Steve Canny said the monorail could damage New Zealand's good reputation for tourism, as Fiordland's World Heritage status could be lost.
A large amount of infrastructure in a relatively unmodified area would reduce the significance of the area, he said.
"The national park is held for specific purposes. Building monorail-type facilities and infrastructure through this area is not at the core of why the land was held and protected."
Fish and Game Southland and Otago representative Jacob Smyth said the recreational use in the conservation area, such as hunting and fishing, would be significantly affected by potential restrictions around the area of the monorail.
A lack of information in the application was spoken of by many submitters, who said that without sufficient information, much of the effect on the ecology in the area would remain unknown.
Outdoor education teacher Paul King said there would be no way to mitigate destroying hectares of vegetation and destroying the values of the land.
"We believe it is impossible to mitigate cutting down trees that are thousands of years old.
"In our view, the applicant is under the impression that the destruction of the natural values of our conservation land can somehow be mitigated."
Southland District Council senior policy analyst Wayne Heerdegen said the council also was concerned about the lack of information in the application.
"The Department of Conservation has allowed a rather skewed assessment of the application, with lower levels of information being given to both the public and the department itself."
Of the 315 submissions, 27 support the proposal.
