Here’s one vision for a stretch of the aging industrial corridor along the North Branch of the Chicago River: A wide-open public park teeming with native grasses, wildlife and people enjoying the outdoors.

Here’s another: An urban “wall” of high rises along the river, with little pockets and slivers of green space.

At least that’s how two North Side aldermen and their allies see the battle that’s brewing over the future of the North Branch, which is expected to see enormous growth.

“What we’re concerned about is that the public will lose access,” Ald. Michele Smith (43rd) told the Chicago Sun-Times Editorial Board Thursday. “Who wanted to stop Grant Park 100 years ago? There were people short-sighted enough to think that we shouldn’t have that public park. We had some brave people with vision who filed lawsuits in order to defend  that.”

Smith, Ald. Scott Waguespack (32nd) and their “great and growing alliance” are making the rounds this week, hoping to drum up support — including from Mayor Rahm Emanuel — to build a 24-acre public park that would run along the river between North Avenue to the south and Cortland Street to the north. The group say the site is the last “large-scale” parcel remaining of the transforming 760-acre stretch along the river, with development “imminent” elsewhere.

And the push comes as a key developer — Sterling Bay — continues its Lincoln Yards project adjacent to the planned park site. The developer also has an option to buy a portion of the proposed park site, said Richard A. Wilson, city design director for the architecture firm Adrian Smith + Gordon Gill.

To date, Wilson said, the city has “no vision” for public open space along the North Branch.

“And that is a big problem,” he said.

Parks appeal not only to residents, but also to companies looking to relocate, he said.

The group’s supporters apparently don’t include Brian Hopkins, the alderman in whose 2nd ward the park would be located.

“It’s a tragedy he’s not here today,” Smith said.

Smith and her supporters say Hopkins has seen the plans and, at one point, liked them.

“We have invited him on many occasions to join the effort, we’ve reviewed the plans with him,” Smith said.

Hopkins disagrees, saying he was neither “invited nor informed in advance” of the proposal.

Hopkins said Smith did show him a “hypothetical rendering of what green space would look like” a few months ago. But if she and Waguespack have fleshed out their plan in more detail, they haven’t shared it with him.

“I’m generally supportive of the concept of what they’re doing. But the specifics of this most recent proposal — they have done that on their own without including my office,” Hopkins said. “I’ve consistently pushed for a greater amount of space for recreational use.”

Hopkins noted that the price tag for all of the community benefits in the North Branch corridor will be “in the hundreds of millions of dollars”.

Recreational space is just one of the items that must be bankrolled, he said.

“We’re going to be spending public money on transit improvements, road improvements and open space and parks,”  he said. “These big-ticket items — you can’t rule them out because they’re expensive. But the process of prioritizing them is something we’re just now initiating. That’s going to require public participation. I will be stewarding the process for the Lincoln Yards development in particular. It’s exclusively in the 2nd Ward. None of this is in the 43rd Ward or the 32nd Ward. I do appreciate the suggestions of my colleagues. But ultimately, this will be a process that is led by the 2nd Ward.”

The mayor is also on board with making open space a priority, a spokesman for his office said.

“The mayor agrees that substantial public open space is essential to the North Branch’s coordinated transition to a dynamic, mixed-use business environment that is reshaping urban waterfronts across the country,”said spokesman Grant Klinzman.

Klinzman said proposals for open space are included in the North Branch “framework plan,” adopted last year by the Chicago Plan Commission.

But Smith, Waguespack and their supporters say the framework doesn’t go far enough.

The park would feature a nature walk, a forest play area, picnic areas, a baseball field, among other things, and would connect to the city’s 606 trail at the north end.

The land for the park has four owners, including General Iron, a Chicago company that does scrap-metal recycling. A representative with the company didn’t return calls seeking comment.

Wilson said the cost to clean up and develop the park would be about $40 million, although the cost to buy the land is unknown, he said.