Tenmile Creek

Tenmile Creek Research Natural Area (RNA) was established to represent a coastal dune mosaic of open sand dunes with tree islands and native stabilized dune grasslands with red fescue. The dune sheet ecosystem is relatively continuous, broken only by the mouths of rivers and open streams. The beach is gently sloped and progresses to a more stabilized foredune and deflation plain system.  The open sand dune habitat includes seashore lupine (Lupinus littoralis) dunes, European beachgrass dunes (Ammophila arenaria), red fescue-salt rush (Juncus lesueurii) grassland, and open sand. The deflation plain wetlands include Hooker willow (Salix hookeriana)/slough sedge-Pacific silverweed (/Carex obnupta-Potentilla pacifica) and shorepine (Pinus contorta)/slough sedge (Carex obnupta). The dune forest habitat includes shorepine-Sitka spruce (Picea sitchensis)/evergreen huckleberry (Vaccinium ovatum), Douglas-fir (Pseudotsuga menziesii)/rhododendron (Rhododendron)-evergreen huckleberry, and Sitka spruce /evergreen huckleberry. Introduction of European beachgrass has significantly altered the coastal dune sheet ecosystem.