Conservation groups and Canmore locals are upset by the province's quiet approval of a wildlife corridor on the southeast edge of the community that will allow a local land developer to keep building homes.

On Tuesday, dozens packed Canmore's council chambers to hear provincial officials explain the decision to approve the Smith Creek Wildlife Corridor on the southeastern edge of town, a plan that sets aside nearly 70 per cent of Three Sisters Mountain Village land.

Sarah Elmeligi, executive director of the Alberta chapter of the Wildlife Society, said not only did the approval come out of nowhere, but the final design of the corridor didn't have enough consultation.

"I still have questions around the functionality of the design," she said. "I'm concerned at the extreme ends how it will connect to other corridors and how animals can safely cross highways without ending up in another human development."

The Three Sisters Mountain Village wants to add 2,200 new housing units to the Smith Creek area and also has plans to build a 2,000-unit resort in the area.

There are about 1,350 units on Three Sisters, with a population of around 3,000.

Originally approved by the province in 1992, the proposed new development would add about 4,200 units, effectively tripling the area's population to around 9,000.

An earlier wildlife corridor application was denied in 2018.

Hilary Young with the Yellowstone to Yukon Conservation Initiative said the plan is still too narrow in areas. She also questioned how human use will be managed.

"If we're looking ahead to a hundred year vision, animals continue to need to move through this corridor and we don't feel like this proposal is the best way to allow animals to move through. In fact, we are concerned that this valley will turn into a block over time," she said.

Young questioned the plan's science, transparency, communication and design.

The approval of a wildlife corridor will allow further development at Three Sisters Mountain Village. (CBC)

Tracy Henderson, a Canmore resident, said there is no room for error in this decision and that if it doesn't work, there's no way to go back to fix it.

"This is a bad decision," she said.

David Taylor, chairman of Three Sisters Mountain Village, said nearly 70 per cent of its land in the area has been set aside for the corridor.

"We want to develop something that the townspeople of Canmore will be proud of and we'll be proud of. Time will tell, but I believe we'll be able to do that," he said.

Taylor said the company has done extensive research on the plans and has engaged with the public while remaining transparent.

The developer still needs to submit area structure plan applications to the town, which will include a public hearing.