Crews began three years ago, when they excavated the lake's basin to rebuild its retaining walls and water pumping system.
The last two years were spent on phase two of the renovation project: new landscaping, lighting, sewers and trails.
People who go to Mount Royal to relax say they're fed up with seeing construction crews and piles of gravel in the area.
"I don't know what they're doing. That's bothering me but what can you do? We don't come here every day," said Montrealer Jagdish Patel.
"We were here about a year ago and we figured things would be pretty much completed by now -- and they're still not," said Yvon Letourneau, a tourist from Sherbrooke.
Les amis de la montagne, a group that works to protect and improve the mountain, thought the work would have been completed much earlier.
"It's constraining. They're also monopolizing one of the parking areas. So we've been waiting for a while — a long while," said Hélène Panaïoti, a spokeswoman for the group.
But the city of Montreal says the work will be finished by Friday — on budget and on time, despite the rainy spring Montreal had.
The city says the only outstanding work will be for stone masons to build a waterfall that will feed water into the lake. That's expected to be done by the end of August.