This installment explores an area just north of San Diego County in Riverside County. This is what Old California looked like before subdivisions and freeways smothered nature. The Santa Rosa Plateau Ecological Preserve is a rare gem waiting to be discovered. Inhabited for up to 8000 years by ancestors of the Luiseño Indians, the preserve traces its recent history to the Rancho Santa Rosa, which was granted to Juan Moreno in 1846. The preserve has long been recognized for its significant resources, which include two historic adobes, rare Engelmann oak woodlands, volcanic soils with vernal pools, running creeks, over 200 bird species, dozens of mammal species, and more than 50 rare, threatened, or endangered plant species.
A recommended hike is the Vernal Pool Trail to the adobes. Early spring, especially early to late March, is the best time to visit. However, a hike here is rewarding in any season. The trail includes a boardwalk over a huge vernal pool where if there has been a good rainfall season and with some luck, fairy shrimp and tadpoles can be seen in early spring. Often, there are garter snakes feasting on these abundant critters, or they may be sunning themselves on the boardwalk. The trail to the adobes is surrounded by green meadows that transform to a buttery tan when they dry out in early summer. As one passes beneath occasional massive blue-gray Engelmann oaks, there is a feeling of having stepped back in time. Chocolate lilies, shooting stars, blue dicks, and many other species are some of the attractions on this hike. Watch for coyotes or badgers. Fat western fence lizards, aka bluebellies, often skitter along the trail or across the volcanic boulders protruding from the meadow.
From the vernal pool trailhead, follow the trail to the vernal-pool boardwalk, then continue on the Vernal Pool Trail 1.7 miles to Ranch Road, and turn right, approximately 0.5 mile to the adobes. Returning from the adobes, follow Ranch House road west to the Trans Preserve Trail, turn left (south). The trail climbs moderately to an oak forest, offering nice views of the valley and distant ridges. When you reach the Vernal Pool Trail, turn right to return to your vehicle.
The preserve began to take shape in 1984, when the Nature Conservancy made the initial land purchase. Over the years, additional purchases have been made by entities including the County of Riverside, Metropolitan Water District, and the California Fish and Wildlife Service. It acts as a mitigation bank, with developers purchasing credits in the land bank to offset housing or other development of the land. Santa Rosa Plateau Ecological Reserve’s primary purpose is to protect the rare habitat, with a secondary purpose of recreation.
- Distance from downtown San Diego: About 73 miles. Allow 1 hour and 15 minutes driving time (Riverside County). Drive north on SR-163 and merge onto I-15 N. After about 67 miles, exit on Clinton Keith Rd. and turn left over the freeway. Follow Clinton Keith Rd. south past the visitor center then keep to the right when it becomes Tenaja Rd., then keep to the left when it becomes Via Volcano until approximately 43311 Via Volcan, where there is a parking lot on the left. There is a day-use fee of $3 for adults and $2 for children. Hours are sunrise to sunset. The visitor center, open 9 a.m. to 5 p.m., Tuesday–Sunday, is located at 39400 Clinton Keith Road in Murrieta.
- Hiking length: 4.5-mile loop. Allow 3–4 hours.
- Difficulty: Moderate. 300-foot elevation gain/loss. No pets allowed. Hikers are allowed on all trails. However, equestrians and mountain bikers are restricted to designated multi-use trails. Facilities available.