The Otter Cove area (just past Otter Cliffs and Otter Point) provides one of the best viewpoints along the Park Loop Road, giving visitors good looks both out to sea and inland. The view to the north takes in the summits of Cadillac (on the left) and Dorr Mountains, with the two peaks separated by a glacial feature called a meltwater channel. Thousands of years ago, a wild river ran here under the ice, carving out this u-shaped notch.
Ahead is the Causeway Bridge, a 215-foot, triple-arch structure built in 1938-39, which curves across the cove. This is the only solid masonry bridge along the Park Loop Road, clad with quarry-faced granite; it was built this way because the engineers thought that exposed concrete might deteriorate in salt water. The bridge includes slots placed in its arches that could be plugged up with boards, to hold back the water and create a shallow, warm swimming area to the north, but such boards have never been installed.
The arches remain open, which allows tidal flows to pass between the Otter Creek inlet and the open sea.
Otter Cove is assumed to be the area where the French explorer Samuel de Champlain stopped overnight in early September 1604, landing his boat on the beach to repair a hole in the hull after he ran onto a rock ledge opposite Otter Cliffs.
Fun Fact: To get technical — in the words of National Park historians — the Causeway Bridge is “essentially a filled spandrel arch bridge with causeway extensions to either side,” one whose “side arches are lined with radiating voussoirs. The parapet walls have no coping courses.”