For folks living in most of New Jersey, the idea of mountains in the low-lying Pine Barrens might seem far-fetched. Many have never heard of the Forked River Mountains of Ocean County, located due west of Barnegat Bay and the Garden State Parkway.

Although they’re called mountains, the Forked River Mountains are actually large sand and gravel hills. They were created 10 million to 15 million years ago when the ocean that once covered New Jersey’s coastal plain retreated, forming rivers that…