Sacramento Valley Bioregion -- An Overview

The Sacramento Valley Bioregion, a watershed of the Sierra Nevada, is rich in agriculture, but also significant as the seat of California's state government. Lying halfway between the Pacific Ocean and the Sierra Nevada, the Sacramento Valley affords convenient travel time to San Francisco and Lake Tahoe. The bioregion encompasses the northern end of the great Central Valley, stretching from Redding to the southeast corner of Sacramento County. Its southern boundary borders the northern edge of the Sacramento-San Joaquin River Delta. Sacramento, the home of California's state Capitol, sits at the confluence of the Sacramento and American Rivers.

Location, Cities, People

Folsom Dam

The broad, flat valley that comprises this bioregion touches nine counties, including all of Sutter, most of Sacramento, and Yolo, and portions of Butte, Colusa, Glenn, Placer, Shasta, Tehama, and Yuba counties. Sacramento, with a population of about 400,000, is the bioregion's largest city and ranks seventh in the state behind Fresno, Long Beach, San Francisco, San Jose, San Diego, and Los Angeles. Other large cities, all smaller than Sacramento, include Redding, Chico, Davis, West Sacramento, and Roseville. More than 1.5 million people inhabit this bioregion, making it fourth most populous of the 10 bioregions, based on 1990 census figures. The cultural roots of the region date from Native American inhabitants, such as the Wintun Indians, to 19th century settlers who established and worked the farms and ranches.

Two of the state's major interstate highways, I-5, the state's main north-south artery, and transcontinental I-80, intersect in Sacramento. Other main highways include U.S. Highway 50, and State Highways 99, 44, 113, 70, and 20.

Tourist Attractions, Industries

Sacramento, capital of the nation's most populous state, is a tourist attraction in itself. The state Capitol in downtown Sacramento houses the offices of the governor, lieutenant governor, and state Legislature. The Capitol is filled with relics of California's colorful history and new displays that reflect contemporary life in each of the 58 counties. Other attractions of the capital city include Old Sacramento on the riverfront, Sutter's Fort, the California State Railroad Museum, cruises on riverboats, and the annual Jazz Jubilee that attracts bands from all over the world. Traveling north, one can see the Sutter Buttes rising 2,132 feet from the valley floor, and visit the national and state wildlife refuges and reserves in the valley's many wetland areas along the Pacific Flyway. On the eastern edge of the bioregion is Folsom Dam and Folsom Lake.

Workers sorting tomatoes

Agriculture, state government, lobbying, and public relations are important industries in the Sacramento Valley bioregion, but only three of the counties -- Sutter, Yolo, and Colusa -- rank among California's top 20 agricultural producers. Still, the valley is known for tomatoes, rice, and olives, among other prominent crops produced in the plentiful fields and orchards. Food canneries, high-technology, and biotechnology play a significant role. Once, the bioregion had a substantial military presence with three Air Force bases, but downsizing changed the picture, closing Mather, then adding McClellan to the closure list, but sparing Beale. Shipping is important in the port of West Sacramento.

Climate and Geography

The changing of the seasons is more evident in the Sacramento Valley than in the coastal regions to the west. Summer hot spells that drive daytime temperatures into triple digits are relieved by cooling “Delta breezes” that carry moist air from San Francisco Bay eastward through the Delta and into the Sacramento area, pushing the mercury back into the more comfortable 80s and 90s. Leaves turn gold during the brief, mild autumn that ends rather abruptly with the coming of winter fog around Thanksgiving. The so-called tule fog blankets the valley for much of the winter season from December into February, keeping temperatures chilled. Except during droughts, rainfall is frequent in winter, but snowfall is unusual because temperatures, particularly in the daytime, normally remain well above freezing.

The Sacramento Valley is flat for the most part, but is situated within distant view of mountains, which are particularly visible on clear days. To the west, the coastal range foothills loom on the horizon, while the snow-capped peaks of the Sierra Nevada can be seen to the east.

The valley's two major rivers -- the Sacramento and American -- carry water that originates in the Sierra Nevada south and west into the Sacramento-San Joaquin River Delta. The importance of the Delta cannot be overstated, for it supplies water to about two-thirds of California's 32 million population. Other rivers include the Cosumnes -- the largest free-flowing river in the Central Valley -- the lower Feather, Bear, and Yuba Rivers.

Plants and Wildlife

Oak woodlands, riparian forests, vernal pools, freshwater marshes, and grasslands provide the major natural vegetation of the Sacramento Valley Bioregion.

The Sacramento Valley is the most prominent wintering site for waterfowl, attracting more than 1.5 million ducks and 750,000 geese to its seasonal marshes along the Pacific Flyway. Species include northern pintails, snow geese, tundra swans, sandhill cranes, mallards, grebes, peregrine falcons, heron, egrets, and hawks.

Chinook salmon

Black-tailed deer, coyotes, river otters, muskrats, beavers, ospreys, bald eagles, salmon, steelhead, and swallowtail butterflies are just some of the wildlife that abounds in this bioregion. Species on the endangered species list include the winter-run Chinook salmon, delta smelt, giant garter snake, and the western yellow-billed cuckoo.

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