The campaign to restore the Everglades has received a boost with completion of a key project that returns the flow of water to 55,000 acres that had once been drained for development. Experts see it as a major step forward in bringing back South Florida’s River of Grass. Patterson Boulevard looks like a road to nowhere. In fact, it’s hardly a road at all, just two dirt tracks into the Florida swampland, hemmed in by willow thickets, pine flatwoods, and cypress forests, passable only in the dry season, and then just barely.  Patterson is part of what’s left of an immense grid of roads built years ago for a failed development that was both massively ambitious and ecologically ruinous. Yet these tracks have now become an entryway into one of the more striking restoration projects in South Florida, a bright spot in nearly three decades of efforts to protect and revive what remains of the greater Everglades ecosystem.…