Cal. Gov. Code § 23143
The boundaries of Santa Clara County are as follows:
Beginning at a point distant North 30° West 1,254 feet from the southwest corner of Sec. 22, T. 5 S., R. 2 W., M.D.B. & M., being the corner common to San Mateo, Santa Clara, and Alameda; thence southeasterly in a direct line to the southwest corner of Sec. 26, T. 5 S., R. 2 W., M.D.B. & M.; thence easterly in a direct line to the point where the center of the Coyote River is intersected by the West line of T. 5 S., R. 1 W., M.D.B. & M.; thence easterly along the center of the Coyote River to a point from which a sandstone monument set on the southwesterly side of the county road leading from San Jose to Oakland, or the state highway, as described in the fieldnotes of the survey of the boundary line between Alameda and Santa Clara, filed June 2, 1873, in the office of the clerk of Santa Clara County, bears North 57° 35' East 4,340 feet distant, more or less; thence North 57° 35' East 4,340 feet, more or less, to said Sandstone monument;
Thence northeasterly and easterly along the boundary line between Alameda and Santa Clara, as described in the fieldnotes of said survey, to the corner common to Alameda, San Joaquin, Stanislaus, and Santa Clara; thence southeasterly following the summit of the Coast Range to the corner common to San Benito, Merced, and Santa Clara, situated in Sec. 21, T. 11 S., R. 7 E., M.D.B. & M., as established by Charles T. Healy, Deputy Surveyor-General of California in September, 1858; thence westerly on the surveyed line between Santa Clara and San Benito to a point on the San Felipe Creek, near San Felipe Lake; thence around the eastern and northern side of said lake to the Pajaro River; thence down said river to the southwest corner of Santa Clara and the southeast corner of Santa Cruz; thence northwesterly, following the northeasterly boundary of Santa Cruz and continuing on the southeasterly boundary of San Mateo, to the head of the South fork of the San Francisquito Creek; thence down said creek in a general northerly and northeasterly direction along the common boundary between San Mateo County and Santa Clara County to a point where said boundary intersects the D 2 center line of the Bayshore Freeway at California State Highway Engineer's Station D 2 322+68.88 P.O.T. as said Engineer's Station and said common boundary is designated on "AS BUILT"-PLAN AND PROFILE OF STATE HIGHWAY IN SAN MATEO AND SANTA CLARA COUNTIES, BETWEEN 0.3 MILE SOUTH OF WILLOW ROAD AND 0.5 MILE SOUTH OF SAN MATEO-SANTA CLARA COUNTY LINE",-San Mateo, Santa Clara Route 68, Section D, A., accepted June 4th, 1958; said intersection being in the boundary of San Mateo County and Santa Clara County as said boundary was established by Ordinance No. 1619, changing the boundary of said counties, adopted October 15th, 1963, by the Board of Supervisors of the County of San Mateo; thence along said boundary as changed, northeasterly 105 feet to the southwesterly terminus of that certain course "South 40° 47' West" designated "Sta. 78+45± End of Work" as said course and said station are shown on "MAP AND GENERAL CONSTRUCTION PLANS OF ZONE NW-1 "NORTHWEST", PROJECT NO. 2 SAN FRANCISQUITO CREEK IMPROVEMENT FROM BAYSHORE HIGHWAY TO SAN FRANCISCO BAY, SANTA CLARA COUNTY FLOOD CONTROL AND WATER CONSERVATION DISTRICT, SANTA CLARA COUNTY, CALIFORNIA. DATED SEPTEMBER 1958"-said plans on file in San Mateo County Engineer's Office in Case 3, H-1691; thence along the center line of said San Francisquito Creek Improvement, North 40° 47' East 128.12 feet, more or less, to Station 77+16.88 of said center line; thence on a curve to the right, said curve having a radius of 305.00 feet and a central angle of 82° 30' an arc distance of 439.17 feet; thence South 56° 43' East 235.00 feet; thence South 61° 43' East 204.00 feet; thence on a curve to the left said curve having a radius of 250.00 feet and a central angle of 49° 00' an arc distance of 213.80 feet; thence North 69° 17' East 404.14 feet; thence on a curve to the left said curve having a radius of 425.00 feet and a central angle of 96° 45' an arc distance of 717.66 feet; thence North 27° 28' West 367.46 feet; thence on a curve to the right said curve having a radius of 455.00 feet and a central angle of 28° 15' an arc distance of 224.38 feet; thence North 0° 47' East 295.00 feet; thence on a curve to the left said curve having a radius of 855.00 feet and a central angle of 13° 37' an arc distance of 203.20 feet; thence North 12° 50' West 1075.00 feet; thence on a curve to the right said curve having a radius of 300.00 feet and a central angle of 65° 35' an arc distance of 343.39 feet; thence North 52° 45' East 1250.00 feet; thence North 50° 20' East 820.00 feet; thence on a curve to the right said curve having a radius of 300.00 feet and a central angle of 20° 00' an arc distance of 104.72 feet; thence North 70° 20' East 500 feet to Station 3±00, designated "Beginning of Project" on said San Francisquito Creek Improvement; thence continuing along last mentioned course North 70° 20' East 300 feet, more or less, to a point in the corporate limits of the City of Menlo Park, as said limits were established by that certain annexation to the City of Menlo Park by Ordinance No. 318, adopted July 14th, 1959, by the City Council of said City; thence southeasterly, easterly and southerly along said corporate limits to the intersection thereof with said common County boundary as the same existed prior to Ordinance No. 1619; thence northeasterly along said boundary to the Point of Beginning.
Ca. Gov. Code § 23143