Exploring California’s Marine Protected Areas: South Cape Mendocino State Marine Reserve, Sugarloaf Island Special Closure, and Steamboat Rock Special Closure

Although California is the most populous state in the United States, much of the coastal area north of San Francisco is undeveloped and provides the perfect escape for those seeking a bit of solitude. Visitors to this area can quite literally get lost on the “Lost Coast”, a wilderness landscape that stretches from Cape Mendocino to the intersection of the coastline with Highway 1 north of Fort Bragg. An iconic trek along this part of the coast takes hikers past old growth redwood forests, steep sea cliffs, and sweeping ocean views.

Even though this area is not heavily impacted by human activities, conservation measures on both land and sea help protect the natural resources found there. The Mattole Tribe has stewarded this area since time immemorial. The coastal waters and nearby Mattole River, named for the Tribe, provided them with bountiful natural resources like salmon, mussels, and seaweed. Members of the Mattole Tribe now belong to the Bear River Band of Rohnerville Rancheria, which is continually working to reconnect Tribal members with the coastal resources around Cape Mendocino and the Mattole River Valley.

map of South Cape Mendocino State Marine Reserve
Map of South Cape Mendocino State Marine Reserve.
CDFW map

Today, the federally managed King Range National Conservation Area encompasses the steep mountains and forests leading down to the rugged coastline. Several state-managed marine protected areas (MPAs) are found along the coastline here. The largest of these Lost Coast MPAs is South Cape Mendocino State Marine Reserve, which safeguards state ocean waters (0-3 nautical miles offshore) near Cape Mendocino. Both living and non-living ocean resources are fully protected in state marine reserves (SMRs). Due to this high level of protection, SMRs are considered the backbone of the California MPA Network.

South Cape Mendocino SMR was implemented in 2012 along with 19 north coast MPAs and six special closures. All 124 MPAs and 14 special closures within the MPA Network were designed to conserve marine life populations and habitats and provide for recreational and educational opportunities. South Cape Mendocino SMR protects nearshore habitats such as rocky shores, beaches, offshore reefs, and sandy seafloor, which can be biodiversity hot spots.

Visiting this section of coast is not for the casual beachgoer. As one of the most remote MPAs in the Network, South Cape Mendocino SMR is only accessible by boat or a long and windy drive out to the coast. Once there, you will have reached the westernmost point of California, which can be subject to fog or strong winds even at the height of summer.

lighthouse plaque
Plaque commemorating Cape Mendocino Lighthouse, Steamboat Rock in the distance.
CDFW photo by S. Worden

Although South Cape Mendocino SMR may not be the best location for a beach picnic, you will find astounding beauty and history associated with this MPA. The treacherous waters off Cape Mendocino often claimed the ships and lives of early explorers, despite the installation of the Cape Mendocino Lighthouse in 1868. Life on this rugged part of the coast eventually proved to be too extreme even for the lighthouse keepers, with frequent windstorms and earthquakes causing constant structural damage. The lighthouse was later dismantled and now stands in the small Lost Coast town of Shelter Cove.

One of the more notable natural features of South Cape Mendocino SMR is an offshore island called Steamboat Rock, sometimes called “Battleship Rock” by the locals because of its distinctive boat-like shape. Steamboat Rock Special Closure provides another layer of protection within South Cape Mendocino SMR. The special closure prohibits human disturbance around the rock from March 1-August 31 annually to protect nesting seabirds and is an important migratory stop along the Pacific Flyway.

Steller sea lions
photo by P. Morris

Another nearby special closure, Sugarloaf Island Special Closure, is found just north of the SMR and is closed year-round to protect one of the few California breeding grounds for the endangered Steller sea lion. Steller sea lions only breed on offshore islands and are rarely spotted on the mainland, so it is critical to protect their offshore habitats.

Although not officially part of the MPA Network, special closures are marine managed areas that act as important conservation tools for marine mammals and seabirds that haul out and breed on offshore rocks and islands along the California coast. Make sure to bring your binoculars so you can view the unique animals that occupy the rocks in these special closures from a safe distance! You may see pinnipeds like sea lions and harbor seals, and seabirds such as the common murre and Brandt’s cormorant. You may even spot the colorful and charismatic tufted puffin!

There are many natural wonders to discover below the waves in this area as well. As a part of the broader MPA Monitoring Program, researchers regularly visit South Cape Mendocino SMR to collect information about its deep reef ecosystems using a remotely operated vehicle (ROV). Deep reefs support a diversity of fish and invertebrate species and often occur at depths that are unsafe for divers to access. ROVs and other video technologies help researchers study the marine creatures that live thousands of feet below the ocean’s surface and determine how they may benefit from MPAs.

It is also possible to observe some of these species from the deck of a boat by joining the California Collaborative Fisheries Research Program (CCFRP) as a volunteer angler. CCFRP connects the recreational fishing community to MPA researchers, and conducts catch-and-release surveys to document the fish species that live in South Cape Mendocino SMR and many other MPAs across the Network. Year after year, the black rockfish reigns as both the largest and most commonly caught fish by CCFRP anglers in this MPA. CDFW and the National Marine Fisheries Service utilize the CCFRP data about rockfish and other fish species to help inform important decisions about fisheries management in California and beyond. To explore all available MPA monitoring data, visit the recently launched data portal!

South Cape Mendocino SMR and its nearby special closures are part of one of the largest ecologically connected MPA networks in the world. California is currently embarking on a comprehensive review of the MPA Network and the MPA Management Program to assess how state MPAs are meeting their ecosystem-based goals. The Decadal Management Review, anticipated for release in January 2023, will be the first evaluation of the MPA Network since its completion in 2012.

South Cape Mendocino State Marine Reserve is of the 124 MPAs in California’s statewide MPA Network. Sugarloaf Island Special Closure and Steamboat Rock Special Closure are two of the 14 special closures in that same network. Please visit CDFW’s MPA website for more information, and sign up to receive updates about the MPA Management Program and the Decadal Management Review.

For more information about ocean fishing and MPA restrictions, visit the ocean sport fishing regulations page.

Report poaching or polluting by calling CDFW’s anonymous tip line CalTIP at 1-888-334-CalTIP (1-888-334-2258).

MPA logopost by Sara Worden, CDFW Environmental Scientist


Learn more about MPAs by diving into the
Exploring California’s Marine Protected Areas series!