EDMONTON -- The group proposing to build a gondola across the river valley says hundreds of thousands of Edmontonians would ride it in the first year alone — but at least one councillor doubts their estimations.

In a feasibility study presented to councillors, Prairie Sky Gondola anticipates 637,000 customers and more than three million trips between downtown and Old Strathcona.

"Those numbers surprised me," said Prairie Sky Gondola president Jeffrey Hansen-Carlson.

The figures surprised Ward 5 Coun. Sarah Hamilton too. "Huh? Sorry, what? 600,000 odd riders?"

Hamilton is concerned the project, which would cost approximately $120 million and take just over two years to build, could flop. She wants the city to proceed with caution.

"What does it say about Edmonton if we have a non-functioning major piece of infrastructure that affects our skyline, that affects how Edmontonians feel about our city?"

Hansen-Carlson and his group insist the project will work, even in a worst case scenario.

"We have sensitivity analysis built into this model where we turn a toggle, really high construction costs, really low ridership and it still makes sense," Hansen-Carlson said.

Ward 10 Coun. Michael Walters said the least the city could do is listen to the group with an open mind.

Councillors will discuss the project on Jan. 28.

With files from CTV News Edmonton's Jeremy Thompson