Total Acres: 802
Total Expenditures: $2,569,000
The Milpitas-Berryessa study area is located along the northern boundary of the county in the westernmost foothills of the Diablo Range. It extends south to Alum Rock Park and west to the valley floor in the vicinity of Tularcitos Creek. Its eastern boundary adjoins watershed lands owned by the San Francisco Public Utilities Commission.
Annual grasslands dominate the slopes that comprise this area. Part of the Pueblo Lands of San Jose, these hills have been used for grazing cattle since the Mexican period.
The Los Buellis Hills, rising in the eastern portion of the study area to an average elevation of 2,000 feet, contain the headwaters of Berryessa Creek, which joins Coyote Creek as it flows toward San Francisco Bay. Calera and Los Coches creeks also drain this region.
Protected lands within the Milpitas-Berryessa study area include the Open Space Authority’s 802 acres directly north of Alum Rock Park, which comprise a portion of Sierra Vista, and the 1,539-acre Ed Levin County Park.
The purchase of the 534-acre Kirk Ranch in March 2000 fulfilled a vision set for Alum Rock Park in 1912 by planner Stephen Child. At that time he recommended buying the highly visible slope and adjoining lands, then known as the Miller and Harlan Ranch, because it was part of the visual framework for the park.
The Authority’s purchase 88 years later secured the vista for all time. With the opening in 2002 of the Boccardo Trail Corridor, the public was invited to climb to the 1,896-foot summit of the ridge to enjoy panoramic views of the valley floor and San Francisco Bay.
The steep, grassy hills hide several deep ravines that shelter tributaries of Upper Penitencia Creek. Five year-round springs also dot the property, creating wetlands that are prime potential habitat for California red-legged frog (Rana aurora draytonii) and California tiger salamander (Ambystoma californiense), both federally listed threatened species.
The property, which supports oak woodlands and stands of chaparral, provides an important wildlife corridor for black-tailed deer, bobcats, and the occasional mountain lion. The grasslands are rich with wildflowers.
Since purchasing the property, the Open Space Authority has reintroduced Corriente cattle into the area to improve the grassland habitat for plant and animal diversity. The Corriente breed can be traced to the first cattle introduced by the Spanish as early as 1493. They are hardy and readily adapt to various terrains and extreme climates.
In 2001 the Open Space Authority added 268 acres east of the Kirk Ranch to its holdings. The property had been used for cattle grazing and limited orchard operations. Its location offers the opportunity to extend trails in the area. Eight springs contribute to an environment that is rich in plant and animal wildlife. A barn on the property is being renovated to serve as a native plant nursery.