Round Valley Regional Preserve

Vegetation

The 2191-acre preserve contains non-native grassland, oak woodland/savannah, shrubland and riparian woodland plant communities. The grassland occurs interspersed with extensive stands of blue oak woodland/savannah. Round Valley itself is primarily annual grassland with valley oak lining the intermittent drainages. Non-native grasses, inadvertently introduced to California by early settlers, comprise the annual grassland flora. The dominant grasses are annual ryegrass, wild oats, soft chess, and ripgut brome, with wild barley, foxtail chess, red brome, silver hairgrass, and annual bluegrass occurring in lesser amounts. Native and non-native wildflowers occur in spring.

The steep, northeastern-facing slopes in the southwestern portion of the preserve support mixed oak woodland and chamise/black sage/manzanita chaparral. Riparian and wetland vegetation consisting of moisture-dependent grasses, rushes, herbs, shrubs, and/or trees occur along Round Valley Creek, which is a tributary of Marsh Creek originating in the uplands surrounding Round Valley.

The southwest corner of the preserve supports mixed oak woodland containing blue, valley, coast live, interior live, and black oak; California buckeye; and California bay laurel.

Riparian vegetation occurs primarily along Round Valley Creek, which the Miwok Trail parallels beginning about one-half mile from the staging area. The creek flows until late spring or early summer, after which the water pools at intervals along the streamcourse. Tree cover along the banks is sparse; vegetation includes spikerush, sedge, rabbitsfoot grass, watercress, curly dock, monkey flower, and willow.

Wildlife

Round Valley Regional Preserve is habitat for a wide variety of wildlife typical of that found in the East Bay Area and also some species more common to the Central Valley. As with all California valley and foothill environments, several species in this area have evolved to survive with only seasonal supplies of water and green vegetation.

Mammals in Round Valley include the California ground squirrel, San Joaquin pocket mouse, Audubon's or desert cottontails, and the endangered San Joaquin kit fox. Round Valley is one of the northern extremes of the kit fox range in California. This shy fox, which is on the Federal and State endangered species lists, lives in the sheltered valley but is subject to isolation and resulting local extinction due to elimination of viable corridors and lack of genetic diversity among the small local population. The kit fox is prey to coyotes and red foxes, and dogs can be a disease vector to the kit fox. Like other scavengers, it is susceptible to secondary poisoning. The challenges faced by the kit fox and its future in the East Bay is one of the primary subjects of the ongoing Alameda-Contra Costa Biodiversity Study, and the Park District is playing a major role in protecting the fox by protecting its habitat in Round Valley.

The preserve is also home to nesting golden eagles, which are protected by State and Federal law. The golden eagles feed on ground squirrels, and with the local burrowing owls, are a state "Species of Special Concern." Burrowing owls nest in ground squirrel burrows and feed on mice and insects.

Ponds and streams in Round Valley support the federally threatened California red-legged frog, western toads, western pond turtles and Pacific tree frogs. These species breed with the onset of winter rains, and burrow into the mud or use rodent holes for hibernation during the dry summer months.

Geology

The bedrock geology of the preserve is Cretaceous Panoche shale and sandstone with deposits of recent alluvium on the surface in valleys and creek drainages. The preserve has small amounts of high-quality soils, located mainly in the level areas along Marsh Creek and in the valley proper. Most of the soil, however, is of a lower quality suitable only for range, wildlife and watershed uses. The Marsh Creek (Mount Diablo) Fault is located about two miles southwest of the preserve. This fault has produced small earthquakes; two recent significant earthquakes (magnitude 5.5 and 5.6) occurred in 1980.

Park Activities

The preserve is open for hiking, horseback riding and bicycling (with some restrictions). The climate at the preserve is arid and temperatures commonly exceed 100 degrees Fahrenheit in the summer months. Be prepared for the summer heat: use sunscreen, wear a hat and loose-fitting clothing, wear good hiking shoes. Drinking water is available at the staging area. Be sure to carry plenty of water with you during your hike.

Camping

One group camping site; 25-person maximum. Camping reservations must be made at least five (5) days in advance. Non-potable water (filter, treat, or boil for human consumption) available at the site. There are leveled tent spaces, picnic tables, and a disabled accessible restroom. It's a 3.6-mile walk from the Marsh Creek staging area. Dependent upon weather and trail conditions, two cars can go to the site to carry materials; no shuttling, campers must walk from the staging area. When not in use as a Group Camp, the site is available to the general public for backpacking. Make reservations for Group Camping.

Dogs

Due to the sensitive nature of the wildlife habitat at Round Valley, dogs are not allowed in the park.