Ronkonkoma Moraine

The Ronkonkoma Moraine, in the geography of Long Island, forms the southern of two ridges along Long Island's "backbone.

"[1] The Ronkonkoma Moraine, a terminal moraine, predates the Harbor Hill Moraine (which reached Long Island during the Wisconsin Glacial Episode); the Harbor Hill Moraine cut through the Ronkonkoma Moraine's western portions.

[2] The Ronkonkoma Moraine and the Harbor Hill Moraine intersect at Lake Success in western Nassau County.

[2] Today, the moraine is most prominent in Suffolk County, where it traverses the center of Long Island and forms the South Fork.

[3]

A map showing Long Island's topography and the generalized locations of the glacial moraines.