In the years following the wildly popular 1893 Chicago World’s Fair, planner and architect Daniel Burnham had a vision to build a manmade island along Chicago’s lakefront. Part of his grand “Plan of Chicago,” Northerly Island was to be a thriving park, a lush, green oasis to balance his only partially realized scheme to overhaul the city with gridded streets and regional highways. The 91-acre stretch, connected to the mainland by a narrow isthmus, was completed in 1925, but 10 years later, the synthetic parkscape become something its maker had never intended: an airport. Now, Burnham’s idyllic vision will return to Northerly Island, as the first phase of the Northerly Island Framework Plan, a proposal to redevelop the abandoned airplane landing strip into an ecologically diverse natural habitat, has been approved.

In 2010, MacArthur Genius Grant winner Jeanne Gang and her firm Studio Gang Architects teamed up with local landscape architecture firm JJR to develop the Framework Plan, which combines heavily researched ecological programs — including new reefs and protected lagoons and savannahs — with more familiar features of the 21st century urban park, such as an amphitheatre. The entire scheme, which functions more like a flexible road map than an exacting blueprint, anticipates 20 to 25 years of fundraising, planning, and construction.

The first phase, soon to be initiated by the U.S. Army Corps of Engineers and the Chicago Park District, focuses on transforming the flat former airplane runway into a variegated topography containing six different ecosystems. Details include a 4.1-acre pond fenced in to protect its inhabitants from invasive species like Asian carp (an issue Gang tackles in her latest book “Reverse Effect.”) Surrounding the pond will be elevated dry-mesic and wet prairies, intended to attract mice, snakes, and small birds. Environmentalists hope that the habitat will provide new nesting areas for over 300 species of birds, luring the animals away from the mainland where they frequently crash into the city’s high-rises.

“To me it’s like a picture of what the city was like before the city was built,” said Jeanne Gang about the first phase in the Chicago Tribune, daring to imagine a pre-Burnham landscape. But as in Burnham’s original vision for Northerly Island, the snapshot of a more primitive past is intended to lure city dwellers as well as natural wildlife and become what Gang calls “a Millennium Park of nature.” Speculative plans for underwater observation cameras, an imported sunken ship, and a designated area for swimming, canoeing, and kayaking point to the island’s true nature, as an extension of a changing city.