It’s hard to imagine today, but before refrigerators and freezers became common, New York City’s food, restaurants, hospitals, and breweries depended on one unlikely place for ice: Rockland Lake.

During the 19th century, this quiet lake in Rockland County became one of the nation’s largest sources of natural ice, supplying millions of pounds each winter to a rapidly growing New York City. At the height of the industry, Rockland Lake was known as “The Icehouse of New York City.”

Every winter, once the ice reached about a foot thick, hundreds of workers took to the frozen lake. Using horse-drawn plows, they carved the surface into a giant checkerboard before cutting enormous blocks of ice by hand.

The blocks were floated through narrow channels, lifted onto conveyor systems, and packed into massive icehouses insulated with sawdust. From there, they were loaded onto trains and barges for the trip to New York City, where they were used to preserve food long before mechanical refrigeration existed.

The arrival of the Rockland Lake Railroad in the 1860s helped turn the lake into the center of a booming industry. Ice harvested in Rockland could quickly reach markets throughout the region, making the county an essential part of everyday life in New York City.

The ice business created hundreds of jobs for local residents, from laborers and railroad workers to barge crews and carpenters. During the winter months, the lakeshore buzzed with activity as thousands of tons of ice were harvested and stored for use throughout the year.

But technology eventually changed everything.

By the early 20th century, electric refrigeration began replacing natural ice, and demand for ice harvested from lakes quickly declined. Within a few decades, the once-thriving industry had disappeared, along with the towering icehouses and rail lines that made Rockland Lake famous.

Today, Rockland Lake State Park is known for its scenic trails, fishing, cycling, and outdoor recreation. Families stroll the shoreline, cyclists circle the lake, and anglers cast their lines where workers once harvested enormous blocks of ice destined for New York City.

Few visitors realize they’re standing at the site of an industry that helped feed and preserve one of the world’s largest cities.

While the icehouses are gone and the trains no longer run, Rockland Lake’s role in New York’s history remains one of the county’s most fascinating—and often overlooked—stories.

Photo image from Yale University