Alum Rock Park
|Alum Rock Park|
View of northern Silicon Valley from South Rim Trail
|Location||San Jose, California|
|Area||2.9 km2 (1.1 sq mi)|
|Operated by||City of San Jose|
|Status||Open except non-holiday Mondays|
Alum Rock Park, founded in 1872, was the first municipal park in the U.S. state of California. Located in a valley in the Diablo Range foothills on the east side of San Jose, the 720 acre (2.9 km²) park offers 13 miles (21 km) of trails, varying from fairly level along Penitencia Creek to sharp switchbacks climbing to the ridges to the South Rim Trail and the North Rim Trail. The narrow floor of the valley includes a visitor center, a small museum/animal rehab facility, picnic areas, playgrounds, lawns, sand volleyball pits, mineral springs, lush plant life, woodlands, creek play opportunities, and occasional group camping.
The ridge trails offer views of Santa Clara Valley and of the valley in which the park is located. Some trails in the park are a part of the Bay Area Ridge Trail; the Todd Quick trail connects with the Santa Clara County Open Space Authority's 1,600-acre Sierra Vista Open Space Preserve.
Alum Rock Park was originally known simply as "the reservation"; it received its current name around the turn of the 20th century when thenardite-containing rocks near its entrance were mistaken for alum.
Penitencia Creek is properly called Upper Penitencia Creek because it no longer connects with Lower Penitencia Creek, which is in Milpitas. The creek also had a different name until the early 20th century; somehow it began to be called by the name of a different creek located to the north, which was so-named because monks (possibly from Mission San José) would meditate by its waters.
From 1921 until unknown, the Santa Clara County Council of the Boy Scouts of America was given exclusive access to 15 acres (61,000 m²) in the park. By the 1960s, the park attracted so many visitors from the rapidly growing Santa Clara Valley that its facilities became overburdened and the natural scenery was damaged. In the 1970s, the park removed most of the buildings, closed off parts of the park, and began emphasizing the park's natural attractions rather than its man-made ones. Much of the stonework remains, however, as do old support structures for a once-existing railroad.
El Niño winter storms caused a landslide that resulted in the closure of the original Alum Rock Avenue entrance in the autumn of 2000; access is currently available only from Penitencia Creek Road.
On October 30, 2007, the 2007 Alum Rock earthquake, a 5.6 earthquake, hit the Bay Area at 8:04 pm Pacific time. It was centered 5 miles (8.0 km) NNE of Alum Rock and at a depth of 5.7 miles (9.2 km). The Hayward Fault and Calaveras Fault converge close to Alum Rock Park. One effect of the earthquake was to cause a previously dried spring to begin flowing again.
The parking lot just outside the entrance kiosk is no longer free - there are self-pay machines that cost $6 per day (the same price as entering beyond the kiosk).
The city closes the park every Monday due to budgetary constraints. It is open on some Monday holidays.
The valley has abundant mineral springs, which were touted as beneficial to people's health. In the late 19th century and through the 1930s, the park was famed throughout the country as a health resort. Through those years and as late as the 1970s, the park featured a natatorium (a huge, heated indoor swimming pool), dozens of private heated mineral baths that visitors could rent, a restaurant, and various other buildings. Many of the springs were enclosed in stonework grottos, and stone bridges were built across the creek. Due to overuse, some of the springs became extinct, and surviving ones became very weak, producing very little output.
The road is maintained jointly by the city and county. Thus, it is a private road maintained at public expense. However, private residents have access to the road. They enter the park and continue on to the rear parking lot. At the end of the parking lot is a metal gate which requires a security code number to enter. Visitors can also walk up the road, but there are various signs which indicate no trespassing.
Fork in the creek
Penitencia Creek has two main sources which converge at the “horse bridge” near the uphill end of the creek trail. The fork from the north is Penitencia and originates from Cherry Flat Reservoir. Alum Rock Falls are about a quarter mile from the fork; however, they have been officially off limits for a few decades because the city of San Jose has not rebuilt the washed-out trail. The creek from the south is Arroyo Aguague and originates in Grant Ranch. Although a couple miles of the creek are within the park, this area too is off limits to visitors.
Youth Science Institute
Opened in 1953, the Youth Science Institute - Alum Rock Science and Nature Center, operated by the Youth Science Institute, features natural history exhibits and a collection of live teaching animals, including several injured and non-releasable hawks and owls that are found in the region. The center offers nature and science school and group programs, after-school science and summer camp programs.
The steep sides of the valley are home to many diverse plants native to California. The south-facing slopes primarily consist of grasses, Poison Oak, sagebrush, and occasional live oak trees. The warm sun on the sagebrush lends a unique smell to the air.
The north-facing slopes are dominated by trees, including Coast live oak, California bay laurel, madrone, and California buckeye. On the valley floor, in the moist areas along Penitencia Creek, bigleaf maple, white alder, and Western sycamore provide shade for the abundant ferns.
Several larger varieties of birds frequent the park, including the Red-tailed Hawk, Turkey Vulture, Wild Turkey, Great Egret, and California Quail. Larger wildlife includes Black-tailed Deer, bobcats, and occasional pumas (Mountain Lions). There has been an increase in the mountain lion population in the San Francisco Bay Area.
Rattlesnakes (specifically, the Northern Pacific Rattlesnake: Crotalus oreganus) are known to be active during the summer months. They can occasionally be seen shading themselves in the foliage along the trails.
- U.S. Geological Survey Geographic Names Information System: Alum Rock Park
- Gudde, Erwin; William Bright (2004). California Place Names (Fourth ed. ed.). University of California Press. p. 10. ISBN 0-520-24217-3.
- Alum Rock Science and Nature Center
- Information from the San Jose Regional Parks brochure for Alum Rock Park (revised June 2002) and from informational signs throughout the park.