in May just above Edith Street bridge, the creek now runs dry by summer, but was once a year-round trout stream (
Alnus rhombifolia) in Redwood Grove. Alder is California's most valuable hardwood, often used for furniture, flooring, or cabinetry. The creek flows through
Redwood Grove, a nature preserve off University Avenue in Los Altos purchased by the city in 1974. In October, 2009 Los Altos contracted with
Acterra to remove non-native plants and revitalize the redwood, oak woodland, riparian and grassland ecosystems by installing native plants, improving soil conditions, and creating habitat for wildlife such as bird houses and native bee boxes. The
coast redwoods (
Sequoia sempervirens) were transplanted by the Halsey family from a location on Summit Road in the
Santa Cruz Mountains and replaced the native willows. At Manresa Bridge at the east edge of Redwood Grove one can see the native
red willow (
Salix laevigata) and
arroyo willow (
Salix lasiolepis) trees. The historic Halsey House, built in the late 1920s by Theodore and Emma Halsey, is a good example of Spanish Revival architecture. The city designated Halsey House a local landmark in 1981 and until recently it housed the Florence Fava collection of Coastanoan or
Ohlone Indian artifacts from a creekside archeological excavation in Los Altos Hills (now moved to the Los Altos History House). On June 16, 2010, the Los Altos City Council finalized the purchase of of creekside property from Delbert and Marlene Beumer, who wanted to provide a safe pathway connecting
Shoup Park and
Redwood Grove. Riparian vegetation was described in the 1989
Adobe Creek Restoration Plan. Existing native riparian trees include
willows (
Salix species),
California sycamore (
Platanus racemosa) in Redwood Grove and near the ranch manager's house at Hidden Villa,
white alder (
Alnus rhombifolia) (one large specimen in Redwood Grove – see photo),
cottonwood (
Populus) at the top of the Moody Creek tributary,
bigleaf maple (
Acer macrophyllum),
California buckeye (
Aesculus californica),
California bay laurel (
Umbellularia californica) and
California walnut (
Juglans californica).
Steelhead trout (
Oncorhynchus mykiss) occurred historically in Adobe Creek. The earliest report touted the trout in the Sportsman's Gazetteer in 1877. This very early report makes rumors that Adobe Creek's trout were introduced extremely unlikely since the first trout hatcheries in California did not propagate any trout until the 1870s, and much of their production was shipped to hatcheries out of state. A physical specimen was collected in 1893 by Wilbur Wilson Thoburn,
Stanford University Professor of
Bionomics, and is preserved in the California Academy of Sciences collection. In 1898
John Otterbein Snyder,
ichthyologist and Stanford Professor of Zoology, also collected steelhead trout specimens in
San Antonio Creek (now Adobe Creek). A 1909 land office brochure promoted Los Altos for its "never-failing mountain trout stream, trout caught a few feet from kitchen doors". According to old-timer accounts, locations below Hidden Villa that held spawning steelhead included the large cement pieces downstream from the Foothill Junior College paint shop outflow and cut banks below Interstate 280, in the perennial reaches of Adobe Creek stretching downstream to just above Redwood Grove. A 27-inch steelhead trout (see main photo) caught by boys in June, 1956 about two blocks from Van Buren Avenue (now Van Buren Street) is the last historical record of this salmonid ascending Adobe Creek to spawn upstream of El Camino Real. Steelhead spawning runs were partially blocked by construction of the tidal gate in the Palo Alto Flood Basin at the mouth of Adobe Creek in 1957. This barrier was only partial, as according to the
California Department of Fish and Game (CDFG), steelhead were caught by local fishermen during 1985, 1986 and 1987 in Mayfield Slough at the confluence of
Matadero and Adobe Creeks; and at least six steelhead were noted passing the tidal gates at Mayfield Slough in the Palo Alto Flood Basin in April 1987. Finally, the trash rack at the tidal gate at the mouth of Mayfield Slough in the Palo Alto Flood Basin continues as an intermittent complete barrier to fish passage when it is closed. Four species of native fishes have been collected from Adobe Creek in 2011:
California roach (
Lavinia symmetricus),
Sacramento sucker (
Catostomus occidentalis occidentalis),
three-spined stickleback (
Gasterosteus aculeatus), and
prickly sculpin (
Cottus asper). Leidy reported the fish still inhabiting the Adobe Creek's lowest reach in 2007 – native California roach, Sacramento sucker, three-spined stickleback, and non-native
common carp (
Cyprinus carpio),
rainwater killifish (
Lucania parva), and
western mosquitofish (
Gambusia affinis). A 2011 fish survey utilizing electrofishing showed only native fish above El Camino Real: the reach above Redwood Grove and the Manresa Lane bridge in Los Altos included California roach, Sacramento sucker and three-spined stickleback – an assemblage that generally includes steelhead trout in other Bay Area streams. Further upstream, the diversity of the fish assemblage steadily diminishes due to passage barriers and reduced stream flows from diversions and wells: at Moody Road just above Foothill College, only California roach and three-spined stickleback were collected, at Rhus Ridge bridge in Los Altos Hills only three-spined stickleback were collected, and at the Francemont Avenue bridge and along the Adobe Creek Trail at Hidden Villa no fish were found. == Palo Alto Flood Basin ==