It's being billed as a once-in-a-lifetime opportunity to celebrate Cootes Paradise, Hamilton Harbour and the Niagara Escarpment while commemorating Canada's 150th birthday.

A Day on the Bridge will see the historic McQuesten High Level Bridge closed to automobile traffic June 11 for a series of activities and events culminating with a gala fundraising dinner for the Cootes to Escarpment EcoPark System.

The ecopark system is an effort to establish a protected, permanent and connected natural land sanctuary from the harbour to the escarpment. The system takes in the Royal Botanical Gardens, Dundurn Park, Princess Point and Cootes Paradise. More than $260,000 has been raised so far.

"By taking a moment to stop and enjoy the view of nature from the bridge on June 11th, my hope is that we will all be reminded of the beauty and importance of this green space to our cities and our lives. Because if it isn't protected, it could disappear," said Patrick Bermingham, a nature enthusiast who dreamed up the idea.

Alison Copoc, the vice-president and program manager of the event, said the original plan was just to have a dinner on a Friday night.

Dreschel: A $300 dinner on the bridge is far too pricey

But the city felt that closing the road on a weekday would cause too much traffic havoc, so Sunday was chosen instead.

That meant "we could make it more or less into two events, the free activities during the day and the dinner later on," she said.