In Vancouver Friday, they unfurled a 167,000 name petition calling on the provincial government to repeal the Park Amendment Act, passed into law last May.
The Act allows for research in provincial parks, but many fear that could lead to mining, logging, or even pipelines.
Joy Foy of the Wilderness Committee says the changes will only benefit corporations, some of which are already planning projects.
"You've got a logging company demanding to be able to put logging trucks through the park, right past the campgrounds and the picnic grounds," said Foy.
Environment Minister Mary Polak says critics are simply misunderstanding the act.
"Industrial development is not and won't be allowed in BC's parks," she promised.
When it introduced the legislation, the government said it would make it easier for researchers to conduct scientific studies and for the film industry to use parks in B.C. as backdrops.
But environmentalists aren't buying it. Protests are planned in a number of provincial parks tomorrow to mark Canada Parks Day.