According to local historian Ken Brady, large boulders were carried down by glaciers during the last ice age and deposited on Long Island. Geologists, says Brady, call them "erratics."
One locally famous example of this can be found in Wading River off of North Country Road. Last week we asked readers to tell us what people in the area called this particular erratic boulder.
One commentor got the name right:
"That is Billboard Rock in Wading River on North Country Road," he wrote. "I have heard it was so named because they used to post town notices on it."
Brady says that this is correct adding in the caption to the photo that "this boulder is known locally as both Billboard Rock and Tuthill’s Rock."
The photograph was taken on Feb. 27, 1901. Notice the buggy on the right of the boulder.
This photo was provided by the Wading River Historical Society.
For more historical photos head over to the Port Jefferson Village Center and check out the new exhibit "Mirrors of the Past: Shoreham and Wading River in Historic Photographs."
There will be more than 120 enlarged photos are display and the show is sponsored by the village of Port Jefferson, village of Shoreham, Wading River Historical Society and the Port Jefferson Village Center Conservancy. Show runs through Feb. 28.
Free admission. Call (631) 802-2165 for additional information.