A large piece of greenery on the eastern borders of Toronto has finally been slated to become a national site after decades of lobbying from politicians and nature lovers.

Rouge Valley, some 10,000 acres on the border between Scarborough and Pickering, was vaunted as an urban national park by Prime Minister Stephen Harper's Conservative government in its throne speech on Friday.

"In this, the 100th anniversary year of our national parks system, our government will create significant new protected areas. It will work with provincial, regional, municipal, aboriginal and community stakeholders toward establishing an urban national park in the Rouge Valley of eastern Toronto," the document said.

"Looking to the future, our government will engage a broad range of stakeholders on the development of a national conservation plan, to move our conservation objectives forward and better connect all Canadians with nature."

The area consists of a mix of river valley, creeks, forests, meadow and rural landscapes within the Rouge River, Petticoat Creek and Duffins Creek watersheds in the Greenbelt. It represents Canada's largest natural environment park in an urban setting.

The area is also home to a diverse mix of wildlife, from coyotes and wolves to beavers and trout.

The designation will protect the natural area from future development.

"It truly is, by a historic fluke, almost an untouched wilderness area, a small wilderness area on the edge of the city of Toronto," Toronto Coun. Glenn De Baeremaeker said.

Although De Baeremaeker said he has been fighting for this designation for 25 years, he said it was worth the battle in the end.

"It has taken a couple of decades, but to see this in writing, in a government document, in a throne speech telling the nation what they are going to do is fabulous," he said.

The designation follows a consultant's report commissioned by the the Rouge Park Alliance last year that said "transitioning the park into Canada’s first near urban national park is the best way to preserve and enhance this vitally important area."