Portola Valley is an incorporated town in San Mateo County, California, United States.

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.

[7][8] The area's written history dates back to 1833, when a square league of land was given to Domingo Peralta and Máximo Martínez by Governor José Figueroa to form the Rancho Cañada del Corte de Madera.

He built a 7,341 foot long aerial tramway from his house to the top of Skyline in 1894 though it was removed after his death in 1900.

[10][11] In 1886 the name Portola-Crespi Valley was bestowed on the area from the then community of Crystal Springs (now under Crystal Springs Reservoir to the then community of Searsville (in the area of the present day Jasper Ridge Biological Preserve); Crespi is for Juan Crespí, a Franciscan friar with the Portolà expedition.

[13][14] In late 2021, this assessment declared that Portola Valley needed to allow for the construction of 253 new housing units over the next 8 years.

[6] Previously, Portola Valley's exclusionary zoning has not allowed any multifamily housing, resulting in a town that is much whiter and wealthier than average for the area, (75% white vs. 35% in San Mateo county as a whole), with the median household income at $250,000 and the average home costing $3.8 million.

[6] By December 2024, fiscal issues arising from the higher costs of using consultants to do the jobs of employees who quit, the costs of lawsuits fighting residents who oppose new housing, and an expected 60% increase in costs for the policing contract with the San Mateo County Sheriff’s Office, led some to consider dissolving Portola Valley and merging it with the county or another nearby city, Woodside.

[13][14] Portola Valley is located on the San Francisco Peninsula on the eastern slope of the Santa Cruz Mountains.

The town is west of Interstate 280 and the southwest boundary is along Skyline Boulevard which more or less is the ridge of the mountains.

Woodside borders it to the northwest and Palo Alto to the southeast The unincorporated subdivision of Ladera is adjacent to the northern boundary of the town.

According to the United States Census Bureau, the town has a total area of 9.099 square miles (23.57 km2), 99.98% of it land and 0.02% of it water.

[21] The Alpine Inn, also known as Casa de Tableta, Rossotti's or Zott's, is one of the oldest existing drinking establishments in California; it started around 1852 when Felix Buelna built it as a gambling house.

[32][33] The trail network includes the 235 acre Coal Mine Ridge Nature Preserve which is private property, but, by agreement with the town is set aside as open space.

There were 1,895 housing units at an average density of 208.4 per square mile (80.5/km2), of which 1,392 (79.7%) were owner-occupied, and 354 (20.3%) were occupied by renters.

[44] Federally, Portola Valley is in California's 16th congressional district, represented by Democrat Sam Liccardo.

[45] Politically, Portola Valley leans slightly Democratic based on voting patterns for past presidential elections.

[47] For law enforcement, Portola Valley contracts with the San Mateo County Sheriff's Office.