One day in the spring of 2017, an art exhibit of sorts went up at 344 Main Street in Beacon, N.Y. A local artist had festooned the fence surrounding the building, under construction, with printouts of a Facebook post that had generated 1,000 comments. The post concerned the front wall of the building, which encroached six feet into the sidewalk. The comments were not positive.

“The sidewalk was reduced to two feet,” said Dan Aymar-Blair, a resident of Beacon. “A woman with a baby carriage wouldn’t even be able to get past it.”

“It was a flash point,” he recalled recently. “A bunch of our neighbors started looking into what construction is planned, what’s at the planning board, what kind of projects are being discussed, and we discovered that there were a thousand new units coming online.”

Beacon, recently remade from a faded industrial city on the Hudson River into a bohemian weekend destination around 2003 with the arrival of Dia:Beacon, one of the largest modern art museums in the United States, is now either selling out to gentrification or reclaiming its midcentury stride, depending on whom you ask.