The Hudson River Greenway between 133rd Street and 135th Street in West Harlem is closed until December, with users instructed to use 12th Avenue as a detour during the greenway’s busiest warm-weather months.

Detour signage has been placed on the greenway as users approach the closed section, though our tipsters said there was no warning signage in advance of the closure.

The closed section is along a seawall bulkhead, while nearby sections are not immediately adjacent to the riverfront. It also passes a Department of Sanitation facility and a natural gas facility, both of which are located on the river and connected to the path by pier structures.

This isn’t the first time the Parks Department, which manages the Hudson River Greenway, has shut down sections of this key cycling artery to Upper Manhattan. A few years ago, Parks banned biking on greenway access paths linking to Riverside Park, but later reversed the decision. Last year, rehabilitation of a bridge over the Amtrak corridor threatened to shut the path entirely north of the George Washington Bridge. After a nor’easter last November, the the department decided to shut the path altogether.

Streetsblog has asked the Parks Department why the path is closed and what kind of work will be taking place there. We’ll let you know if we hear anything back. Update: A utility company will be performing construction work at the site, according to Parks Department spokesperson Phil Abramson. “The work is not happening on parks property but they need room for construction staging,” he wrote in an e-mail.