Morro Bay State Park
Map SatelliteThis State Park is divided into two separate areas, the main section of the park, which fronts on the bay only, and the sand-spit wild area, which divides the bay from the ocean.
On the sand spit, which is some 5 kilometers (3 miles) long and has dunes up to 25 meters (85 feet) high that, in some instances, are unstabilized, the dominant vegetative cover is the coastal strand community, particularly in the southern two-thirds. The predominating shrubs include silvery lupine, Lupinus chamissonis, mock heather, Ericameria ericoides, coyote brush, Baccharis pilularis, and lizard tail, Eriophyllum staechadifolium. The uncommon Senecio blochmaniae is found here.
In Shark Inlet, at the southern end of the spit, there is a salt marsh with spiny rush, Juncus acutus ssp. leopoldii, which here may be at its northern distribution limit. Two rare plants are found in the southern end of the spit, Arctostaphylos morroensis and Erigeron blochmaniae, as is the endangered Morro Bay kangaroo rat, Dipodomys heermanni morroensis. Numerous seabirds and waterfowl feed and rest on the spit.
While much of the main park is developed, three areas are of note, the extensive salt-water marshes to the south and east, the heron rookery in the western portion, and the Black Hill natural area. Vegetation in the dissected salt marsh is similar to that of Morro Bay , with pickleweed, Salicornia virginica, the dominant. In the undeveloped upland sections of the park, the Black Hill natural area, the dominant vegetation is coastal sage scrub with such plants as California sagebrush, Artemisia californica, deer weed, Lotus scoparius, black sage, Salvia mellifera, and buckwheat, Eriogonum parvifolium. Chaparral and grassland are found in this section also. The rare Layia jonesii occurs here.
Some 250 species of birds have been sighted in the vicinity of the park. The great blue heron, Ardea herodias, and the black-crowned night heron, Nycticorax nycticorax, roost here in one of the more important rookeries along this section of the coast.
Geologically, much of the park is on Pleistocene marine deposits or terraces; however, Black Hill and Cerro Cabrillo, a portion of which lies within the park, are volcanic intrusive plugs dating from the Tertiary. (See Los Osos Valley Volcanic Peaks). On Black Mountain there are excellent examples of exfoliation slabs of the intrusive dacite, large, thin masses of rock formed by the release of pressure when the dome was uplifted and the surrounding Franciscan formation rock eroded away.
On White Point, Chumash Indian mortar holes are visible on the rocks.
Integrity: Campsites and other facilities, including a golf course, marina and trails, have been developed within the park. There is also a natural history museum here. In the developed portions the vegetation is primarily exotic.
Use: Research, educational, observational, present.
Ref: Gerdes, G. L., et al. 1974. Natural Resources of Morro Bay, Their Status and Future. Calif. Dept. of Fish & Game Coast. Wet. Ser. #8, 103 pp.
September 1976
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman
