Los Trancos Open Space Preserve is a 274-acre (1.11 km²)

open space preserve An open space reserve (also called open space preserve, open space reservation, and green space) is an area of protected or conservation ethics, conserved land or water on which Real estate development, development is indefinitely set aside. The ...

, located in San Mateo and Santa Clara Counties,

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, near

Los Altos Hills, California Los Altos Hills (; ''Los Altos'', Spanish for "The Heights") is an incorporated town in Santa Clara County, California, United States. The population was 8,489 at the 2020 census. The town is known for its affluence and expensive residential ...

. The preserve contains about 5 miles (8 km) of

hiking trails A trail, also known as a path or track, is an unpaved lane or a small paved road (though it can also be a route along a navigable waterways) generally not intended for usage by motorized vehicles, usually passing through a natural area. Howe ...

, of which 2.1 miles (3.4 km) are open to

equestrians Equestrianism (from Latin , , , 'horseman', 'horse'), commonly known as horse riding ( Commonwealth English) or horseback riding (American English), includes the disciplines of riding, driving, and vaulting. This broad description includes the ...

, and none are open to

bicycle A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered transport, human-powered or motorized bicycle, motor-assisted, bicycle pedal, pedal-driven, single-track vehicle, with two bicycle wheel, wheels attached to a ...

s. The area was once a part of a 13,300 acre (53.8 km²) rancho. The preserve's acreage was purchased by state senator Louis Oneal in the early 1900s, who raised horses there. It was sold to a developer in the 1950s. Power and water lines were run to the property in the 1960s, but development was abandoned when the city of Palo Alto discovered the high cost of providing city services to the area. The preserve was acquired by the

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

in 1976. While the preserve is relatively small compared to other preserves and parks in the area, it has one notable feature: about one mile (1.5 km) of the

San Andreas Fault The San Andreas Fault is a continental Fault (geology)#Strike-slip faults, right-lateral strike-slip transform fault that extends roughly through the U.S. state of California. It forms part of the tectonics, tectonic boundary between the Paci ...

runs underneath it. Several series of markers throughout the preserve indicate where the ground has broken during various

earthquakes An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they c ...

. Additionally, a 1.5-mile (2.4 km) trail follows the main break caused by the

1906 San Francisco earthquake At 05:12 AM Pacific Time Zone, Pacific Standard Time on Wednesday, April 18, 1906, the coast of Northern California was struck by a major earthquake with an estimated Moment magnitude scale, moment magnitude of 7.9 and a maximum Mercalli inte ...

. This trail includes several interpretive stations that point out various quake-caused features and phenomenon. Guided "quake walks" are held about once a month. Just northwest of Page Mill Road, the preserve protects the headwaters of Los Trancos Creek, a tributary of

San Francisquito Creek San Francisquito Creek (Spanish for "Little San Francisco"—the "little" referring to size of the settlement compared to Mission San Francisco de Asís) is a stream, creek that flows into southwest San Francisco Bay in California, United State ...

External links

Los Trancos page at MROSD
GPS/Mapping data, hike description & photos Midpeninsula Regional Open Space District Protected areas of San Mateo County, California Protected areas of Santa Clara County, California Nature reserves in California Santa Cruz Mountains {{SanMateoCountyCA-geo-stub