Los Trancos Creek (meaning "barriers" or "cattle guards" from the Spanish "Las Trancas") is a

creek A creek in North America and elsewhere, such as Australia, is a stream that is usually smaller than a river. In the British Isles it is a small tidal inlet. Creek may also refer to: People * Creek people, also known as Muscogee, Native Americans ...

that flows northerly from

Monte Bello Ridge Black Mountain is a summit on Monte Bello Ridge in the Santa Cruz Mountains of west Santa Clara County, California, south of Los Altos, California, Los Altos and Los Altos Hills, California, Los Altos Hills, and west of Cupertino, California, Cu ...

on the northeast slope of the

Santa Cruz Mountains The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central and Northern California, United States. They form a ridge down the San Francisco Peninsula, south of San Francisco. They separate the Pacific Ocean from ...

to its confluence with San Francisquito Creek at

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, United States. The creek forms the boundary between northwestern

Santa Clara County Santa Clara County, officially the County of Santa Clara, is the sixth-most populous county in the U.S. state of California, with a population of 1,936,259, as of the 2020 United States Census, 2020 census. Santa Clara County and neighboring Sa ...

and southeastern

San Mateo County San Mateo County ( ), officially the County of San Mateo, is a county located in the U.S. state of California. As of the 2020 census, the population was 764,442. Redwood City is the county seat, and the third most populated city following Daly ...

History

High winter flows in Los Trancos Creek are diverted by

Stanford Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is considere ...

's Lagunitas Diversion Dam just downstream from Rossotti's to Felt Lake. The lake is actually a reservoir that lies west of Interstate 280 and bounded by Alpine Road and the Pearson Arastradero Preserve on Arastradero Road. Felt Lake was constructed in 1876 by gold miner and lumber dealer Job Johnston Felt, who bought 700 acres in northern Santa Clara County to farm. It was his dream to build two water companies, San Francisquito and Los Trancos. Felt built the original diversion from Los Trancos Creek to Felt Lake. By the mid-1880s, and facing opposition to his plans, the elderly Felt abandoned the water company idea and sold the farm to Timothy Paige, who quickly sold it to Leland Stanford Sr. in 1887. The university later added a larger dam to hold irrigation water for the growing campus.?

Watershed

Los Trancos Creek drains an area of about and consists of about of channel. Its headwaters are protected by the

Los Trancos Open Space Preserve Los Trancos Open Space Preserve is a 274-acre (1.11 km2) open space preserve, located in San Mateo and Santa Clara Counties, California, near Los Altos Hills, California. The preserve contains about 5 miles (8 km) of hiking trails, of ...

just northwest of Page Mill Road. Los Trancos Creek has several minor tributaries. Named tributaries are Bovet Creek, Buckeye Creek, and Felt Creek. Bovet Creek begins in Coal Mine Ridge Open Space Preserve of Portola Valley Ranch, and is named after the local prominent ranch owner, Antoine Francis Bovet, who died in 1973. Bovet Creek flows down along Valley Oaks Street in Buckeye Creek is a small tributary that enters from the east with origins in Palo Alto Foohills Park, including Boronda Reservoir. Felt Creek is another small ephemeral tributary which begins in the Pearson-Arastradero Preserve, then passes north under Arastradero Road where it was dammed to create Felt Lake. The Felt Lake Diversion ditch begins at the intersection of Arastradero and Alpine Roads and diverts high winter Los Trancos Creek flows to join Felt Creek before the latter enters Felt Lake. Below the reservoir, Felt Creek rejoins Los Trancos Creek just north of Interstate 280. Of interest, Felt Creek may have historically joined Los Trancos Creek just north of Arastradero Road on the 1876 Thompson & West map of Santa Clara County. The next watershed to the west is Corte Madera Creek, another tributary of San Francisquito Creek. The confluence of Los Trancos Creek with San Francisquito Creek occurs just below Piers Lane Road (between Interstate 280 and the Stanford Golf Course) in a small residential island of land belonging to Menlo Park within Stanford's lands.

Ecology

In 1929 Stanford installed a diversion dam on Los Trancos Creek to its Felt Lake water storage reservoir. The dam, located just below the intersection of Arastradero and Alpine Roads, blocked access of

anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...

steelhead trout (''Oncorhynchus mykiss'') to over of pristine upstream spawning grounds. In 2009,

completed construction of a new fish screen and ladder as the previous fish ladder was an "Alaska Steep Pass" designed for much higher flows. The upper watershed is wholly protected within the

just northwest of Page Mill Road and east of Skyline Boulevard. Spawning steelhead in Los Trancos Creek below the Felt Lake diversion dam vary from zero in drought years to several hundreds in wetter years and occurs from February to April. Steelhead spend two years in freshwater before heading to the Bay and field studies in the Stanford portion of Los Trancos Creek have found hundreds of young trout ranging from ~140 per mile to nearly 600 per mile. From 2016 through 2020, a pair of

bald eagle The bald eagle (''Haliaeetus leucocephalus'') is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (''Haliaeetus albicilla''), which occupies the same niche as ...

s (''Haliaeetus leucocephalus'') has nested in a large eucalyptus tree near Felt Lake and the Pearson-Arastradero Preserve.

Hiking

Excellent hiking from the Piers Lane parking area on Alpine Road crosses over San Franciscquito Creek and Los Trancos Creek just above their confluence and proceeds to the

Stanford Dish The Stanford Dish, known locally as the Dish, is a radio antenna in the Stanford foothills. The dish was built in 1961 by the Stanford Research Institute (now SRI International). The cost to construct the antenna was $4.5 million, and was fund ...

. It is open from sunrise to sunset and no bicycles or dogs are allowed. The Coal Mine Ridge of Portola Valley Ranch has many walking (closed to biking) trails. The headwaters of Los Trancos Creek are easily accessed from Page Mill Road in the Los Trancos Open Space Preserve of the

Midpeninsula Regional Open Space District Formed in 1972 by voter initiative, the Midpeninsula Regional Open Space District (MROSD) is a non-enterprise special district in the San Francisco Bay Area. It has acquired and preserved a regional green belt of open space land and provides o ...

and include the Lost Creek Trail, the San Andreas Fault Trail, the Page Mill Trail and Los Trancos Trail.

References

{{Reflist

External links

San Francisquito Watershed Council

prepared by the Oakland Museum of California
Los Trancos Open Space Preserve at Mid-Peninsula Regional Open Space Preserve
Also see:

Los Trancos Woods Portola Valley is a town in San Mateo County, California. Located on the San Francisco Peninsula in the Bay Area, Portola Valley is a small, wealthy community nestled on the eastern slopes of the Santa Cruz Mountains. History Portola Valle ...

Stanford University places Palo Alto, California Rivers of San Mateo County, California Rivers of Santa Clara County, California Rivers of Northern California Tributaries of San Francisquito Creek