Clatsop Spit is a large sand spit on Oregon’s northwest Pacific coast at the mouth of the Columbia River, formed after the last ice age as rising seas and sediment from the river were shaped by seasonal winds, waves, and shifting dunes into a broad sandy plain. Once marked by active dunes, the landscape changed in the 1930s when grass and shrubs were planted to stabilize the sand, and much of the former dune field became known as Clatsop Plains. The spit is also closely linked to the perilous waters at the Columbia’s mouth, where numerous shipwrecks, including the General Warren and Peter Iredale, reflect the deadly hazards of the Graveyard of the Pacific.