Frost turns an ordinary shoreline scene into a quiet standoff between nature and human thought. As waves die, they rise again as sand dunes—brown and dry—and move inland like the sea in another form. Their target is a fishing town: where drowning failed, the sea tries to bury people in solid sand. The speaker lets the sea be personified as a cunning “she” who knows coasts but misunderstands people. Changing shape cannot cut off mind. If sailors can leave a ship for the sea to sink, they can just as easily abandon a hut to the dunes. Each lost shell only frees them to think. The mood is eerie but wry and calm, with an edge of human defiance.
Sand Dunes — Summary
Sea waves are green and wet, But up from where they die, Rise others vaster yet, And those are brown and dry.
They are the sea made land To come at the fisher town, And bury in solid sand The men she could not drown.
She may know cove and cape, But she does not know mankind If by any change of shape, She hopes to cut off mind.
Men left her a ship to sink: They can leave her a hut as well; And be but more free to think For the one more cast off shell.