Jesse Fried • Jun 14, 2017
The Atlantic Highlands are a steep headland at the northern end of NJ's stretch of oceanfront. Along with Sandy Hook, they mark the location of a sharp, almost 90 degree turn in the state's outline, where the Raritan Bayshore meets the Atlantic coast. These rugged hills feature steep slopes dropping as much as 266 feet directly to the salt water, contrasting sharply with the rest of our flat to gently rolling coast. Protected from the ocean only by the thin barrier beach of Sandy Hook, they are almost completely surrounded by salt water: the broad Raritan Bay to the north, the narrow channel of the tidal Shrewsbury River inland of Sandy Hook to the east, and the Navesink River's calm estuary to the south. To the west, the upland continues intermittently inland for 14 miles, but gets generally less steep and dramatic away from the coast.
These hills are geologically within NJ's coastal plain, composed of sediments deposited along the edge of the continent on and off during the past 100 million years. The resistent caprock underlying the hilltops is very recently deposited (Tertinary) ironstone. The formation of ironstone is a very cool process, turning ordinary sedimentary deposits into a very hard rock long after their original deposition, by water dissolving minerals, seeping through the rock, and forming a new matrix, but it's beyond the scope of this website.
A beautiful and diverse upland forest still covers much of the hills, sharing space with suburban neighborhoods. Tulip poplars and mixed oaks, with a dense understory of holly in some places, cover the long, steep, south-facing slopes above the sandy beaches of the Navesink River. In the interior of the hills, northern hardwoods such as sweet birch, southern hardwoods like hickories, and occasional white pine, join the oaks and tulip trees. An extensive mountain laurel understory, including some very tall, old, beautiful individual, crowns the hilltops. Spicebush is also common, attesting to the richness of the forest. A stand of alders, with an understory of some flowering wetland shrub whose name is unknown to me, covers the lower slopes of the steep north-facing hillsides that climb directly out of the Raritan Bay, giving way to red oaks higher up. This is probably a naturalized population of European Alder, the only such stand I've seen on the East Coast. How beautiful to walk through such a lush forest, feeling a cool ocean breeze, and getting a view through the branches of blue water extend towards the horizon.
World War II era weaponry is located on some of the hilltops, which is fun to walk around. The area around it is cleared and maintained, and so provides some of the best unobstructed views of the ocean. A good portion of the hills are contained in Monmouth County's Hartshorne Woods County Park.