From Provincetown to the Dune Shacks and the Parabolic Dunes

Parabolic Dunes area with the Pilgrim Monument far back on the the left side—seen from a dune at High Head Beach on September 11, 2021

The National Park Service map of the Cape Cod National Seashore shows a Parabolic Dunes area between East Harbor (North Truro) and the Atlantic Ocean, which stretches roughly from the Dune Shacks Trail to Pilgrim Heights. Although the parabolic dunes can be reached by car via High Head Road off Route 6 in Truro, I decided to get there by hiking from Provincetown via the Old Colony Railroad Trail, Dune Shacks Trail and the seashore beaches. This year—after all the summer rain—I found the Dune Shacks Trail partially flooded along its sections between the dunes.  

Dune shack seen from Dune Shacks Trail 

Outer Cape: Dune Shacks Beach narrowing and bending southeast towards High Head Beach

This is a great day trip. Half of the way—from Dune Shacks Beach across secluded beaches to High Head Beach—goes alongside ocean surf. I enjoyed this part by wading and sea-life watching. 

Seals in the surf between Dune Shacks Beach and High Head Beach

You may want to check the tide table before going, since along certain stretches you may find it difficult, if not impossible, to escape from strong high-tide waves over the steep, cliff-like front dunes. Also, some beach sections are closed off from early March to mid-August to accommodate shorebird nesting.    

So, where are the parabolic sand dunes? And how do I identify one? I surfed the web beforehand.

I found a cool, downloadable document on the NASA Earth Observatory site describing various sand dune types for kids [1]. If it has been written for kids, it can't be wrong for adults. Since my dune knowledge is not on firm ground, I used this file to get started. Parabolic dunes are introduced as follows: 

Parabolic dunes typically form near the ocean on sandy beaches with some vegetation. Beach grasses and plants anchor the tips of the dunes, and the wind blows out the center. This forms crescent-shaped dunes with tips facing into the wind.

The tips are also called horns. A Wikipedia schematic illustration shows coastal parabolic dunes with their steep windward side facing the ocean surf and the leeward slip-face facing away from the ocean [2].

There is a characteristic dune at High Head Beach. I already noticed it from farther away, while approaching this sandy beach, which has been said to provide an off-the-beaten-path experience and is praised as a spectacular beach for fishing, wildlife watching and relaxing in the golden sand [3]. Spotting and identifying parabolic dunes is not mentioned. I tried anyway. 

The dune I approached is shown in the picture below.

Slightly crescent-shaped dune at High Head Beach with tips (horns) a little closer to the waterfront than the upper crest

This crescent-shaped dune has a steep and barren front including the sand-only blow-out area. The steep side is facing the Atlantic Ocean. The crest and slip-face is covered with dune grass. Is it a typical parabolic dune? Is it in its early stage? Since dunes reshape and move over time, any label is just a snapshot classification. This makes sandy scapes so interesting. Indeed, windblown shapes are mind-blowing—whether parabolic or othercurved.

References and more to explore

[1] Shifting shapes of sandy scapes. NASA Earth Observatory, August 2020. URL: https://earthobservatory.nasa.gov/blogs/eokids/shifting-shapes-of-sandy-scapes/. Note: the link to download the PDF document is right below the first picture.

[2] Schematic of coastal parabolic dunes. Wikipedia. URL: https://en.wikipedia.org/wiki/Dune#/media/File:Parabolic_dune.jpg.

[3] Kinlin Grover: High Head Beach: North Truro's Hidden Gem. The Beach Times - Kinlin Grover Vacation Rentals, April 7, 2021. URL: https://www.vacationcapecod.com/blog/high-head-beach-north-truros-hidden-gem.