A small Valley, some fifteen miles long and a few miles wide, at the southern terminus of the Sierra Nevada Mountains on the southeast corner of the San Joaquin Valley of Central California, harbors an unobtrusive little gem of private stewardship, the Kern River Preserve. Here, in the sleepy, dusty little community of Weldon, in the northeast corner of Kern County, with a population so tiny that there are no numbers for its inhabitants in the AAA Road Atlas, lies the largest contiguous riparian forest remaining in all of California. One of the state’s and, indeed the West’s, rarest ecosystems or habitat types has been preserved through the years by caring private ownership. The riparian habitat harbors a number of rare wildlife species dependent upon riparian forests. The second-largest population of the California-endangered Western Yellow-billed Cuckoo in the state (and one of the largest in the West), one of the two largest populations of the federal and California-endangered Southwestern Willow Flycatcher in California, and the northern-most California population of Summer Tanager all thrive on these private lands. There are also rare or endangered species of turtles, butterflies and plants on the Preserve.
The South Fork Valley runs east-west, following the course of the South Fork of the Kern River. The Valley lies at an elevation of between 2,600 and 2,700 feet. It is almost entirely surrounded by various spines of the Sierra Nevada, most of which are included within the Sequoia National Forest. The headwaters are to the north, high in the Sequoia’s 9-10,000 foot peaks, and the pristine waters first flow south and through the Golden Trout Wilderness and the Dome Land Wilderness before tumbling over a falls and onto the private ranchlands of the Valley. The South Fork flows for about twenty miles until it merges with the larger Kern River which flows south some 50 miles from its source in the 12,000 foot peaks at the south edge of Sequoia National Parkland and through the Golden Trout Wilderness. Most of the north-south reach of the rivers is roadless, and what few roads exist are closed in winter by the Sierra’s deep snows. The river then tumbles down through the spectacular Kern River Canyon, through the city of Bakersfield and continues west to end in the remnant marshlands of Buena Vista Lake, Lake Webb, and the Tule Elk State Reserve. Before the massive water use and water diversions of this century, the Central Valley, especially its southern end, once held the largest system of streams, marshes, lakes, wetlands, floodplains and riparian forests west of the Rockies.
At least it did during the centuries when the Tubatulabal Indians roamed the Kern Valley, and when the first miners entered the Valley in the first few years after 1850 on the heels of the California Gold Rush. During the 1860s, ranchers entered the Valley and carved out homesteads in the broad meadows, wet fields, and grassy hillsides along the South Fork. Ultimately, ranching and hay farming proved more profitable and long lasting than the search for the mother lode. While busy, brawling mining camps were scattered over the mountain sides, the Valley prospered with cattle pastures, hay fields and agricultural crops serving the miners.
One of the first settlers in the Valley was Andrew Brown, who homesteaded the Andrew Brown ranch in the 1860s. In the 1870s Brown built the Valley’s first flour mill, which still stands on the property today.
Eventually the mining activity diminished, but ranching continued as a successful and harmonious way of life along the South Fork. Little changed until the late 1940s when the federal Government and the State of California decided that the steep, narrow upper end of the Kern River Canyon would make a spectacular site for a dam and reservoir. Completed in 1953, this federally-funded water project created Lake Isabella, one of the largest reservoirs in California. The lake is now a major recreation area. Boaters, sailors, fishermen and campers, flood the campgrounds at the lake. The water project is run by the U.S. Army Corps of Engineers and the Kern River Water Master. The Corps subsequently transferred 1227 acres at the eastern end of the reservoir to the U.S. Forest Service (USFS) for a wildlife area. The USFS operates the South Fork Wildlife Management Area, which is part of the nation-wide system of “Watchable Wildlife Areas”, originated by Sara Vickerman of Defenders of Wildlife and identified by a unique highway signage, with the outline of white binoculars on a brown background, placed by state departments of transportation. In addition to the public campgrounds, tourists utilize the private campgrounds and motels in the area. Nevertheless, the population of the Valley is still relatively small – only several thousand. The 57 mile long drive from Bakersfield up the narrow, winding two-lane road, while a spectacular scenic treat, is harrowing. People have to go out of their way to get there.
Another circumstance that helped preserve the Valley’s outstanding riparian forest was that the creation of Lake Isabella only flooded the lowermost few miles of the South Fork of the Kern. Some fifteen miles of magnificent forest still stretched east up the Valley across a series of cattle ranches to where the river tumbled over the cliffs and into the Valley.
Conservationists and environmentalists in California have been deeply concerned about the loss of riparian habitat within the state and the accompanying disappearance of the plant and animal species that both make up and depend upon that habitat. As the natural meanders, ox bows and flood plains have been straightened, channelized, rip-rapped, concretized and leveed, and as the rivers have been dammed and Valleys flooded, the unique wildlife species dependent upon riparian habitat have rapidly declined, resulting in many plants and animals being placed on state endangered species lists or on the federal Endangered Species List. The California Riparian Habitat Joint Venture reports that “Riparian habitats . . . have the highest diversity and productivity of landbirds of any terrestrial habitat type in the western United States . . . . Of the landbird species currently listed as endangered, threatened, or of special concern in California, almost half . . . require riparian habitat during some part of their life cycle.” Riparian forest habitat is also home to 83 percent of the amphibians, 40 percent of the reptiles, and 42 percent of the mammals that occur in California.
Probably no state has suffered more destruction of its riverine habitat than California, where vast governmental water projects have transformed the natural water flow of the great Central Valley into a man-made irrigation, flood control and water delivery system. Within the private sector, farmers and developers have drained wetlands and cleared riparian vegetation. This is especially true in the San Joaquin Valley, at the southern, warmer and dryer end of the Central Valley. Overall, it has been guesstimated that 90-95 percent of the original one million plus acres of riparian forest and brush in California has been destroyed. The riparian forests of the Central Valley underwent even greater destruction, with only 2-5 percent of the approximately 900,000 acres remaining. While such numbers are always problematic, they certainly underscore the nature of the loss.
In the late 1970s word came that the Andrew Brown Ranch might be coming on the market. The heirs were no longer interested in attempting to eke out a living in the hard scrabble business of cattle ranching. The family sold the property to the Kern County Land and Cattle Company. With the land under new ownership and facing the possibility of development, The Nature Conservancy of California, jumped at the opportunity to acquire it. With funding from Chevron USA, Getty Oil Co. (Texaco), and the W. M. Keck Foundation it purchased the approximately 1,600 acre A. Brown Ranch for $2,500,000.
In 1980 the core ranch was purchased. Thereafter, the Conservancy initiated an active program of land trades with adjacent landowners, initially with the Prince Ranch, just down river, and the Sprague Ranch to the north. With the Prince Ranch, they traded pastureland in front of the preserve, but within their fencelines, and grazing land on hillsides to the south across Rt. 178, for some additional bottomland. Such swaps of large amounts of grassland for smaller amounts of riparian forest brought the Kern River Preserve to its current size of 1,133 acres.
The Kern River Preserve is a long, narrow property encompassing about 4 miles of riverbottom. The west boundary abuts the U.S. Forest Service South Fork Wildlife Area with two parking areas and Watchable Wildlife viewing areas as well as the eastern end of Lake Isabella where the South Fork flows into the reservoir. This is necessarily an unstable area, including a draw-down zone, as well as a large area fluctuating between drought-driven mud and grass flats and flooded expanses of forest during prolonged wet periods. The eastern end extends upstream into the Onyx Ranch.
The Preserve Headquarters consists of a number of buildings including an office building, a research center, an interpretive center incorporating a museum display and information center, the manager’s home, a guest quarters, and equipment buildings and sheds. The office building/visitor center is the original Mountain Hotel which was moved from the Old Kernville town site before the filling of the reservoir. The parking lot holds an information and display board, a log for bird and wildlife sightings, a guest book and a plaque commemorating the establishment of the Preserve and the original donors. Self-guided nature trails, with a printed nature guide and signed trail stops, run through the original bottomland riparian forest zone as well as newly reforested areas.
One of the first actions undertaken was the fencing of the existing riparian forest areas in 1981 and the subsequent reduction and careful management of cattle grazing, including the development of a compatible grazing strategy. Extremely dense understory along the river came back in a short time. The Preserve staff note that on their arrival the riparian vegetation was so thin that it was possible to see traffic on the highway from their headquarters during the summer. But the understory grew back so quickly that in short order a dense curtain shielded the HQ, even in the winter.
Another initial undertaking was a research program, including floral and faunal inventories, and vegetative monitoring. A particular concern was the identification and removal of exotic plant species, which have the potential to crowd out and even replace native species. Four trees that are of special concern are Saltcedar, Giant Cane, Russian-olive and Chinese Tree of Heaven. The first three create such dense stands that they clog stream channels and cause flooding. Saltcedar and Giant Cane also create heavy fuel loads and can become dangerous fire hazards.
In addition to reducing biodiversity through the loss of native plants, stream clogging and fires, alien species often provide far less food, shelter and nesting sites for native wildlife. From the beginning, the Nature Conservancy sought to remove every exotic tree they found in the Preserve.
The managers have worked to develop the trust of neighboring landowners in coordinating efforts to get rid of exotics on their lands as well, thereby reducing the likelihood of their return and maintaining the total biotic integrity of the Valley.
One of the conditions that has made the South Fork Kern River Valley so significant has been the relative absence of invasive, non-native vegetation within the Valley. According to the Kern Valley Resources Conservation District, the Valley “. . . is one of the few remaining areas in the Southwestern United States where these aggressive weeds have not become firmly entrenched.” The extent of the problem is evident by the fact that even the beaches and sandbars in the bottom of the Grand Canyon have been extensively invaded by aliens, with miles upon miles of dense thickets of Saltcedar. Elsewhere in Southern California many of the river forests are now dominated by Giant Cane.