Special Supplement: Highway to the Flyway, July-September 2007

Ponds 1 (in foreground) and 1a (bottom right) are connected to San Pablo Bay (above) by a narrow channel under Highway 37. Formerly the first step in Cargill's North Bay salt production process, the ponds are now managed to provide critical habitat for shorebirds and dabbling ducks. Photo by Saul Chaikin.

By John Hart

Along the gentle arc of the northern San Pablo Bay shoreline, one of the region's least loved highways traverses one of its most fascinating landscapes. California Route 37, the 21-mile link between Vallejo and Novato, is a fast, straight road that in its eastern half becomes a slot between concrete medians and bone-rattling, textured shoulders designed to keep your mind on your driving. Better to be in the passenger seat, for the country you are traversing deserves far more than a stolen glance. Rich, flat, laced with shining waters, very nearly uninhabited, it is one of the three regions adjoining San Francisco Bay where vast historic wetlands could be brought back to life—and are.

While much diminished from its former extent, the great arc of wetlands north of San Pablo Bay is still a significant destination on the Pacific Flyway for large numbers of shorebirds and waterfowl, as seen here at Petaluma Marsh. Photo by Scott Hess.

At two places along the route, the road rises slightly to cross ridgelines running southeast toward the Bay: Black Point in Novato—between the valley of Novato Creek and the Petaluma River, and Sears Point—marking the divide between the Petaluma Valley and the region drained by Tolay Creek, Sonoma Creek, and the Napa River. Why call these modest heights "points," you may wonder. A look at 19th-century maps makes things clear. Sears Point and Black Point were once points indeed, long fingers of dry ground intruding into a watery world.

At the time of European contact, San Francisco Bay was bordered by tidal marshes around much of its complicated perimeter. In three places, that spongy fringe bulged landward into marsh complexes miles deep. One of these great wetlands enwrapped the southern arm of the Bay. A second extended north from Suisun Bay on the fringe of the Central Valley. The third bordered San Pablo Bay from Point San Pedro in Marin County to the mouth of the Carquinez Strait at present-day Vallejo. The three areas were of similar size, each originally close to 70,000 acres. Today, the original tidal marsh landscape in each has almost entirely disappeared. Each area has nonetheless retained substantial value as habitat, especially for birds. And in each area the task of the new century is to build on what has survived, bringing back chunks of the still-greater richness that was.

The Rise and Fall of the Marshes

San Francisco Bay was not always encased in marshes. When the sea began to poke in through the Golden Gate at the end of the last Ice Age, it gained ground rapidly, flooding the series of linked valleys that make up the floor of the modern Bay. Any peripheral wetlands that formed were quickly inundated. By 3,000 years ago, however, sea level rise and the advance of the waters had slowed. Mud banks on the margins of the Bay were colonized by cordgrass, alkali bulrush, pickleweed, and other plants adapted to life half-in, half-out of variably salty water. Once established, the marshes could keep pace with continuing sea-level creep. They thickened themselves, shedding their own dead growth to build ever deeper peat soils; they also shifted horizontally, expanding upslope, making up for any territory eroded at the open water margin.

Dowitchers are among the many shorebirds that spend their winters in the marshes and mudflats of the San Pablo Baylands. Photo by Rick Lewis.

At the moment of European contact, the San Pablo Bay marshes were an impressive sweep indeed. They also contributed a good share to the biological wealth of the region. Pouring bits of themselves into adjoining waters, they nourished a proletariat of invertebrates and small fish and, through them, all the animals higher up the food chain. Within their confines, the marshes contained a special habitat of wandering, branching, mud-floored sloughs. These provided shelter and food for young fish, including Chinook salmon and steelhead; for crustaceans like Dungeness crab; and for birds such as diving ducks and the California clapper rail. The higher lying parts of the marshes, "the marsh plains," had their own communities of marsh-dependent animals, like the San Pablo Bay song sparrow and the salt marsh harvest mouse. Before there were man-made salt evaporation basins, there were natural ones—shallow pools, or "pannes" set into the marsh plain that intermittently filled and dried out, attracting salt-loving birds like eared grebes and avocets. At the land edge, the marshes merged into other damp environments: brackish and seasonal wetlands, moist grasslands, and willow groves and thickets along creeks. This mosaic of habitats helped make San Pablo Bay a major destination and stopover on the Pacific Flyway, that heavily traveled avian thoroughfare between summer breeding grounds to the north and wintering grounds to the south.

The Human Imprint

The Native American groups of the region, speakers of Miwok and Patwin, had important village sites on the rims of the marshes, such as Olompali at Novato and a major settlement at Vallejo. They harvested food and fiber from the wetlands and plied the channels in tule boats. After conquest and colonization, the new masters planted their settlements at the same peripheral locations, natural transfer points between commerce on land and on water.

Soon, though, the settlers wanted less water and more land. Beginning in the 1850s, they began diking off marsh areas between the sloughs and converting them into islands for agricultural use. Dredges moved along the waterways, lifting loads of mud and depositing them on the adjacent marsh border. It took several goopy passes to create a reasonably stable levee. A final breach would be closed at a low tide, when as much water as possible had drained from the new land. In about two years, the soil would be dry enough to work.

The heyday of "reclamation," as this process was called, was the last third of the 19th century. In the summer of 1870, 12,000 acres were being leveed off on the west side of the Napa River. In 1890, it was the turn of the marshes along Sonoma Creek. By 1930, the last major dike had closed.

Just one big piece of original marsh along San Pablo Bay was left intact. Along the Petaluma River, there remained 4,000 acres of bulrush and cattails, pickleweed and saltgrass, laced with sloughs and dotted with perched, salty pools. Surrounded by unusually deep waterways, this tract survived the boom years of dredging and then passed into the hands of duck-hunting clubs who liked it the way it was. As a result, the Petaluma Marsh is the largest block of prehistoric tidal marsh remaining in California. Here scientists carried out the first large studies of West Coast marshes to see how they function in a relatively natural state.

In addition to this and a few smaller relicts, the region acquired some newly made marsh. Nineteenth-century hydraulic mining in the Sierra Nevada sent a billion cubic yards of sediment moving slowly down the rivers tributary to the Bay. Much of this settled out in northern San Pablo Bay, creating mudflats where none had been before. When Highway 37 was constructed in 1922, much of its course still ran right at the bay's edge, where a wave-constructed berm served as the fundament for a road-bed. Soon the road was buffered by a new marsh strip. Formed very quickly, this wetland lacks the intricate circulation system and habitat variety of a Petaluma Marsh. But unlike many such second-generation marshes, this one was not, in its turn, diked and drained. By default, it became a last stand for such creatures as the salt marsh harvest mouse and the black and clapper rails.

After 1930 the outlines of the modern landscape were set, but subtler alterations continued. With the closing off of marsh regions that once flooded and drained with each tide, the sloughs carried less and slower-moving water. As a result, they silted in, narrowing and shallowing. Waterways once navigable on any tide were not so any more, or could be maintained only by expensive dredging.

On the newly made land, too, a process set in that is observed whenever marshes are "reclaimed." Exposed to the air, the soil began to oxidize and disappear, a kind of slow fire. The old marsh plain lay about three and a half feet above sea level. The typical farm field in the region now lies four or five feet below. In the first decades, fields could be kept dry by opening simple valves at low tide, allowing ponded water to exit into the bordering sloughs. From the 1950s on, active pumping was required.

Fortunately for the birds, the drying-out program was never fully realized. Some owners allowed their land to "pond up" in the fall for the benefit of ducks and duck hunters, several were permanently reflooded for the same purpose, and other chunks reverted to wetland (if not to fully tidal marsh) as the primitive dikes around them sprang leaks.

In 1952, Leslie Salt purchased a rank of ranches along the Napa River and converted them to an open-air salt factory. In a system that operated for 40 years, San Pablo Bay water was tapped and transported northward through a series of ponds, growing ever more saline by evaporation. It was a miniature version of the great salt operation in the South Bay. As in the South Bay, these ponds drew birds by the thousands.

The Choice for Conservation

By the 1960s, the North Bay margins were an utterly different world from the one the Indians and colonizers knew. They remained, nonetheless, a world apart and somehow out of mind. Cities boomed at either end of Highway 37; to the north, at the old wetland margins, vineyards expanded their grip on the landscape. But the land along California 37 looked much the same in 1978 as it did in 1958: tawny hayfields, a few duck clubs, glints of water in sloughs, and plenty of "No Trespassing" signs. The highway offered no inviting exits for exploration. Hunters and some bird-watchers knew the ways into the depths of the region, mostly from the north, where narrow roads reached landings on the banks of obscure channels. Naval installations at Mare Island near Vallejo and at Skaggs Island, a secret communications complex on Sonoma Creek, also helped preserve the status quo.

But the land was too close to the metropolis for this stasis to hold. Though not very well suited to conventional development, the territory invited urbanization in the particular form of the "lagoon residential community," with fingers of filled land for house sites, dredged channels and locks for boats, and a dock in every backyard. The first of these communities in the North Bay, Bel Marin Keys on Novato Creek just south of Highway 37, was started in the late 1950s. A second, the Bahia neighborhood west of the Petaluma River, was begun ten years later. In the 1980s, a huge lagoon residential plan for the Cullinan Ranch, adjoining Highway 37 just west of the Napa River, seemed headed for construction until conservationists blocked it in court.

It was this controversy that really focused the region's attention on the San Pablo Baylands. Clearly a broader initiative to protect this valuable zone was called for, including more acquisitions, agricultural conservation easements, and cooperation with farmers to increase the value of their fields for migratory birds.

Government agencies and private land trusts had in fact been assembling property in the region since the 1970s. In 1974 the San Pablo Bay National Wildlife Refuge was created, covering mostly the "new" marsh and mudflats south of Highway 37. In 1978 the California Department of Fish and Game (DFG) purchased the heart of the old Petaluma Marsh, and has been building its holdings in the area ever since. In the 1980s, the Sonoma Land Trust began putting together a cluster of lands at the mouth of the Petaluma River. In 1991, Cullinan Ranch was added to the federal refuge. In 1994, DFG became the owner of the most extensive piece of all: the 10,000 acre salt pond system.

In the new century, two controversies, one at the west end of the baylands and one smack in the middle, brought citizen activists out in force and cemented the region's future as a conservation zone.

At Bahia on the Marin side of the Petaluma River, only part of the planned lagoon residential community had been completed, and there weren't enough waterfront home-owners to pay for the frequent dredging required to keep channels open. Boats lay heeled over on the mud. A developer, supported by the City of Novato, now proposed to round out the half-built boater's paradise. The Marin Audubon Society led the dogged opposition. In 2003, after Novato's voters revoked the development approval in a referendum, Audubon engineered the purchase of the undeveloped portions of the sprawling property, including wetlands and a stretch of rare blue oak woodlands.

Another scare came in 2002, when headlines announced a plan for a casino on Highway 37 at Sears Point, a site held for decades by increasingly frustrated speculators. The group behind it was the Federated Indians of Graton Rancheria, which, as a federally recognized tribe, enjoyed immunity from normal government land-use controls. Once made aware by conservationists of what their plan would do to prospects for restoring the San Pablo Bay shoreline, the tribe graciously ceded the field to the Sonoma Land Trust, which—with the help of many partners and donors—was able to buy the land.

With these acquisitions, the jigsaw puzzle of preservation around San Pablo Bay was rapidly coming together. "We've turned the corner," says Beth Huning of the San Francisco Bay Joint Venture, the umbrella group of private, public, and nonprofit baylands stakeholders. "The big central pieces have been preserved. Now it is time to restore them."

The Remaking of a Landscape

But what form would that restoration take? Could the old wetlands, now known as the "San Pablo Baylands" and recognized as keys to the ecosystem's future health, simply be brought back, and to what extent should they be? What about salt ponds and other managed waters of recognized value to fish and birds? How would farms fit in?

In 1999, the conversation was crystallized in a document dryly titled Baylands Ecosystem Habitat Goals. A better title might have been Turning Back the Clock, or maybe You Can Go Home Again (Almost). What is proposed is a substantial undoing of a century of land "reclamation," a massive breaking of dikes, and surrender of hard-won terrain to the tides of San Francisco Bay. Regionwide, total salt marsh acreage would more than double. For every two acres of fully tidal marsh, about an acre of managed wetlands would also be retained and improved.

Along San Pablo Bay, marsh area would grow from 16,000 to 38,000 acres. The expanded marsh would sit on the dome of the bay rather like a three-pointed crown: a wide strip along the entire bayfront, with major prongs up the Napa River on the east, Sonoma Creek in the center, and the Petaluma River to the west. Alongside and sometimes within the spreading marshes, large areas would remain as pools, "muted" marshes with controlled tidal flows, or seasonal wetlands. The various habitat restoration projects in the area—60 at last count—are now to be seen as aspects of one great undertaking: the building of a diverse new landscape.

Twenty years from now, drivers along Highway 37 will be seeing more marsh, more bird-studded open water, more riparian vegetation, more wild hillside. They should also have better access to what they see. At a minimum, it will be safe, in more places, to stop and look around. The "North Bay Flyway Highway," as it is now being styled, will be more worthy of the name. The Bay Trail, mostly on diketops south of the highway, should be complete as an alternative, nonmotorized corridor. Canoers and kayakers will have more places to launch on journeys into the sloughs and the bay.

And what about 50 years from now? By then we will know the outcome of the great gamble implicit in all of today's efforts at ecosystem repair: that restoration will be able to keep up with, and reduce the damages of, global warming. The latest report of the Intergovernmental Panel on Climate Change predicts a 20-inch rise in sea level over the next half-century. That's the midrange estimate; it might be more, but that is quite enough. In places around the Bay where marshes, old or regenerated, are thin strips alongside structures like roads and seawalls, they are likely to be pinched out of existence. Will Travis of the Bay Conservation and Development Commission expresses the fear: "The Bay by default will become a big reflecting pool." Hope lies in a few places like the San Pablo baylands, where the undeveloped zone is wide and where marshes, if established early, can thicken and shift their margins inland as they need to.

The rising sea may also disrupt the planned two-to-one proportion of tidal marshes and managed wetlands. Diked pools and muted marshes lack the wild marsh's ability to adjust to a changing environment; they require maintenance, and the costs of that may climb along with the water level. But true marshes also earn their keep as soft seawalls, absorbing the energy of waves and high tides, and as spongelike absorbers of water in flood events, which are expected to become increasingly frequent.

In the long run, the recent strange perturbation of the North Bay wetland fringe—its decimation by diking, its brief augmentation by sediment eroded from faraway mountains, its hollowing-out by subsidence, its dramatic re-flooding and restoration—may look like a brief interruption in a millennial marshland story.

You will find this article and additional features in the July-September 2007 issue of Bay Nature, available through our online store or by calling (888)4-BAYNAT or
(888)422-9628. You may also purchase the current issue at bookstores and other retailers in the San Francisco Bay Area.

SIDEBAR: Marsh Gumplant

Defining the edge of a shifting body of water like San Francisco Bay, whose exact extent changes with every tide, every season, every storm, can be tricky business. In our region the regulators sometimes fall back on a botanical criterion. In doubtful cases the Bay can be said to begin and end with the presence of a modest but important plant, the salt marsh gumplant, Grindelia stricta var. angustifolia.

As you would guess from its large yellow late-summer blossom, gumplant belongs to the sunflower family. As suggested by its name, it exudes a sticky, aromatic resin, which the Indians used to treat rashes. While cordgrass thrives under daily inundation and pickleweed favors perennially wet soil, gumplant likes its root zone better drained. It is found on higher or dryer ground within saltwater wetlands, like the natural levees that form alongside tidal channels—or on artificial dikes that have had their height reduced to improve habitat. The appearance of gumplant at Sonoma Baylands was an early sign of progress in its evolution to tidal marsh. Two to five feet tall, the gumplant is the giant of its zone. At its feet spread shorter plants whose common names evoke the environment they thrive in: saltgrass, alkali seaheath, sea lavender, fat hen. The clapper rail, the black rail, and the salt marsh harvest mouse all move up into gumplant stems for refuge when particularly high tides drive them from the pickleweed. The clapper rail uses the plant's stems and leaf canopies as scaffolding for its nests, the San Pablo song sparrow roosts in its branches, marsh insects harvest gumplant nectar, and the mouse (like many birds) eats its seeds.

The role of gumplant as an edge marker says something about how the Bay has changed. Before their "reclamation," salt marshes faded landwards into brackish marshes and other transitional habitats where Grindelia was scarce or absent. Now most of these buffers are lost, and the typical marsh begins and ends at a steep-faced dike, with a fringe of gumplant climbing it. That's fine for the plant but, because diketops are paths and perches for predators as well, not so fine for the creatures that depend on it for refuge.

SIDEBAR: The Tribe

When Greg Sarris of Santa Rosa, an adopted child, learned that his paternal grandmother was a Coast Miwok, it opened the door to a whole alternative culture. He would soon begin to explore that heritage, absorb it, and work to present it to the world—not as an activist at first, but as a novelist and scholar.

In 1992, he learned of a proposed casino on the shore of Tomales Bay, to be built in the name of a Northern California Indian group under a new law that exempted recognized tribes from local land use controls. Sarris objected both to the use and to the non-Miwok sponsors. "Those were our sacred grounds," he says. "Those people from Cloverdale didn't belong down here."

Sarris spent the next eight years working to organize the legitimate remnants of the Coast Miwok and Southern Pomo Indians, a mixed community clinging to its identity on a scrap of land near Healdsburg. As one of his last acts in office, President Bill Clinton signed the bill—authored largely by Sarris himself—recognizing the Federated Indians of Graton Rancheria.

Greg Sarris. Photo by Alejandro Salazar.

Unfortunately, recognition did not bring a budget with it. After several years of looking for another economic base, the tribe, which had elected Sarris as its chair, turned to the expedient it had hoped to avoid: a casino. A partner was found who acceded to all the tribe's conditions (including the use of green construction and union labor) and located what looked, commercially at least, like the ideal site: the busy, but vacant, intersection of the Lakeville Highway and Highway 37 at Sears Point.

The ensuing furor left Sarris unmoved. But then he read an analysis put out by The Bay Institute, the Sonoma Land Trust, and the Sonoma Ecology Center, showing how the project would doom any hope for a continuous sweep of restored wetlands along Highway 37. Sarris put in a call to Marc Holmes, the Bay Institute's point man for the area. "That single conversation," Sarris says, "changed my mind." The result, a few months later, was an agreement that made the Federated Indians a partner in the preservation of 2,327 acres at Sears Point.

The casino plan (still attracting debate) has been shifted to the urban fringe in Rohnert Park. Sarris is determined to see it through. He is equally determined to use much of the eventual revenue for larger purposes, like purchasing and managing Sonoma County open space. "Our dream," he says, "is to once again take our place as caretakers of our aboriginal lands."

SIDEBAR: The Other Rail

Everybody knows about the California clapper rail, the charismatic (though elusive) endangered bird of San Francisco Bay marshes. The San Pablo Baylands shelter almost half its known population. But here the clapper shares the wetland with its smaller, quieter, and still more elusive cousin, the California black rail, Laterallus jamaicensis coturniculus.

The black rail is sparrow sized—five to six inches long—and dark slate in color, with faint white bars on its sides, a chestnut nape, and a back with prominent white spots. You need good timing and good luck to glimpse it. Researchers estimating its numbers don't even try to look; they listen, broadcasting its call—Grr kkick-kic-kic—and counting the answers they get.

Black rail. Photo by Ian Tait.

The black rail spends most of its life in mature stands of pickleweed or alkali bulrush, where spaces under the canopy allow movement and nesting. The best sites are near creeks or sloughs with slightly higher vegetated ground nearby to provide escape in very high tides: refuge both from the water below and from predators—herons, egrets, harriers—in the air above. The rail itself eats aquatic invertebrates, land insects, and possibly seeds.

While there are outlying colonies on the ocean coast and even in the Sierra foothills, most of the birds are found around San Pablo Bay and in Suisun Marsh. The highest concentrations are in the Petaluma Marsh Wildlife Area and at several points along the Napa River, including White Slough in Vallejo. Though not as near the brink as the clapper rail, the black rail is a California Threatened Species and a federal Species of Management Concern. Its full recovery depends on expanding the number of marshes that are large, remote, and fully tidal: just the kind of living spaces that the San Pablo Baylands can now provide.

John Hart is the author of a dozen books on environmental issues in Northern California, including San Francisco Bay: Portrait of an Estuary (UC Press, 2003) with photos by David Sanger, and Legacy: Portraits of 50 Bay Area Environmental Elders (Sierra Club Books, 2006) with photos by Nancy Kittle. His articles have appeared frequently in Bay Nature.

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