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Science & Nature

Geology

Sinkyone Wilderness State Park lies near one of the most seismically active places on the planet: the Mendocino Triple Plate Junction. Here the Pacific, North American, and Gorda tectonic plates all come together, with lots of folding and faulting.

The park’s beaches are mostly black sand, made up of dark, iron-rich mineral grains and small cobbles and gravels from local Franciscan bedrock. Sometimes a frosting of purple or pinkish garnet sands appears and then vanishes, brought about by the washing action of the surf.

Animals

Red, pinto, and flat abalone inhabit the Sinkyone’s rocky shoreline. Steelhead, coho and Chinook salmon live in tributaries, coastal drainages, streams and river.

The park has a small herd of Roosevelt elk. An earlier herd was exterminated more than a century ago, but these transplants from Prairie Creek Redwoods State Park are thriving and may be found throughout the park. Photographers beware: bulls can weigh up to 1,200 pounds, and they aggressively guard their harems, especially during mating season in the fall. Females are wary during calving season in May and June. Respect their habitat and observe safely, from a distance.

Black bears are occasionally seen in forested areas; the even more elusive mountain lions roam at dawn and dusk.

Offshore, whales migrate from mid-January to mid-April. Elephant seals, sea lions, and harbor seals haul out along the rocky shoreline. To report a distressed marine mammal, call the North Coast Marine Mammal Center at 707-465-6265.

Amphibians include southern torrent salamanders, giant salamanders, tailed frogs, and yellow-legged frogs.

Overhead, raptors—including red-tailed hawks, Cooper’s hawks, sharp-shinned hawks, golden eagles, northern harriers, peregrine falcons, northern spotted owls, and osprey—descend from the skies, seeking their prey. Out at sea, brown pelicans, rhinoceros auklets, and their close relatives—tufted puffins—can be seen diving for fish.

Plants

Sinkyone Wilderness has steep Douglas-fir forests close to the coast. Tanbark oak grows on the inland slopes. Coastal terraces are covered with coastal prairie and coastal scrub vegetation. Only three groves of old-growth redwoods survived the logging era: J. Smeaton Chase Grove southeast of Bear Harbor, School Marm Grove north of Wheeler, and Sally Bell Grove on Little Jackass Creek.

Sinkyone’s redwoods are windswept, twisted, and up to 10 feet in diameter. That’s not especially big by North Coast standards. (Trees more than 20 feet in diameter and 350 feet tall live elsewhere.) However, Sinkyone’s trees are especially picturesque.

More information

For more information about geology, plants, and animals along the North Coast, go to the Redwood National and State Parks website http://www.nps.gov/redw/naturescience/index.htm or to the “In Depth” section of the Humboldt Redwoods Interpretive Association website http://humboldtredwoods.org

To find out about scientific research in California's redwood parks, go to Save the Redwoods League’s website. http://www.savetheredwoods.org/our-work/study/redwood-research/redwoods-research.