A thin barrier spit known as Sandy Hook fronts the ocean side of the Navesink Highlands, separated from the base of the most seaward hills by the narrow tidal channel of the Shrewsbury River.

[3] (USGS topographic map Marlboro, NJ shows a benchmark at the approximate summit of Beacon Hill with an elevation of 364 feet.

[6] The Mount Pleasant area, generally comprising portions of Holmdel and Marlboro with elevations over 300 feet, induces a slight micro climate.

The hills of the Navesink Highlands are composed of uplifted layers of hardened sands, mud, and gravel from the Atlantic Coastal Plain.

The topmost geologic layer of the Highlands, the Cohansey Formation, is composed of sand, gravel, and erosion resistant ironstone.