The Santa Rosa Plateau is best experienced at the margins. Start out at first light, or end the hike at dusk. Do a full loop hike on the perimeter trails through the transition areas bisecting the bunchgrass prairies, oak woodlands, sage scrub and chamise chaparral plant communities, the riparian streamsides and, of course, the vernal pools in the spring. You'll likely agree that the Santa Rosa Plateau is the crown jewel of the Santa Ana Mountains. My earliest recollection of the Santa Rosa Plateau was just after getting my pilot license in 1974. I was a senior in high school and would fly my 1946 Taylorcraft 500 feet over the rolling hills of the plateau. Due to the Nature Conservancy's acquisition of the 3,100 acre plateau in 1984, it hasn't changed much since. A consortium of conservation and government agencies purchased an additional 4,000 acres in the early 1990s.

Access to the Santa Rosa Plateau is from Interstate 15 in Wildomar just north of Murrieta. Take the Clinton Keith Road off ramp south. Stay on Clinton Keith Road until you are a couple of miles into the foothills approximately 4 miles south of the freeway. The visitor center is accessed from a driveway on your left. Continue straight ahead to reach the Vernal pools trailhead. Clinton Keith Road changes to Tenaja Road, and if you bear left rather than continuing on Teneja Road, you will be on Via Volcano. The trail head is ahead on your left. Park on the roadside and take the trail east to the vernal pools. (See aerial photo). As you pay the $2 entrance fee ($1 for children)and pick up a trail map, reflect for a moment on the fact that you just received the best bargain in southern California.

It's a short hike to the vernal pools which will have water in in the spring in all but the drought years. To determine the water level before you drive to the plateau, go to Tom Chester's excellent and detailed web site. If this link is broken, go to his home page on the Santa Rosa Plateau. There is a boardwalk into the northern area of the largest pools. I prefer to make this hike first thing

Vernal pool

in the morning when there are no crowds, and the warm-colored morning sun lights up the surrounding hills. With a sharp eye, you may be able to spot some of the fairy shrimp which inhabit the pools. As you continue hiking eastward, and before you start descending to the east, you may notice a number of California poppy surrounding the trail. Once you start the descent, you will wind through a brief section of chaparral before descending into the prairie of native grasses and populated with both live and Engelmann oaks. The Santa Rosa Plateau is the best remaining Engelmann oak savanna in southern California. The trail soon makes a "T"at Ranch Road, and you'll make a right for a short distance to the historic adobes.

These buildings date back to the 1800s during the early days of Rancho Santa Rosa after Juan Moreno received a Mexican land grant in 1846. He later sold it to Augustin Machado, and it went through various owners until the Vail family purchased it in 1904. The Vail Ranch included the plateau, and also encompassed what is now Murrieta, Temecula and surrounding areas. The Ranch was sold to a unit of Kaiser Aluminum in 1964 to be part of the master-planned development called Rancho California. Coincidently, I worked in Temecula for Kaiser's real estate group as an intern in the early 1980s while going to college. The Nature Conservancy acquired 3,100 acres of the plateau from Kaiser in 1984. An additional 4,000 acres were acquired by various governmental entities, as well as the Metropolitan Water District from Ranpac, Inc., a residential developer, in the ensuing years.

There are picnic tables and portable toilets at the adobes, so this is a good spot to take a break. To continue the loop and hike through a variety of plant communities, take the Lomas Trail for a (very) short distance north where you will see the windmill on your left and look for the Adobe Loop Trail on your right. The trail parallels Adobe Creek which is densely populated with live oaks, sycamores and an ampleamount of poison oak. Although I think this hike is best in the spring, it is also a great hike in the late fall as the sycamore tree leaves turn yellow. The trail continues to the east and connects with the Punta Mesa Trail just east of the old adobes. Take the Punta Mesa trail east (left). This trail drops into the De Luz Creek drainage where both sage scrub and chaparral plants predominate. Here is an aerial view of this portion of the plateau. You'll see black sage and white sage, Manzanitas, ceonothus and other chaparral shrubs. This trail abuts the Mesa De Burro research area immediately to the east. This area is closed to visitors due to the ongoing research activity. As the trail turns to the north, you'll transition back into bunch grass prairie. Soon you'll come to a disused ranch road, Monument Road. Take this road/trail to the left (west) as it heads up hill. Along with the native grasses and oak trees, you will see patches of prickly pear cactus on both sides of the trail. Keep an eye out for deer which are common on the prairie. If you hike this trail in the late summer to early fall, you are almost sure to see a number of tarantulas walking on the trails looking for mates. For some reason they grow them large out here. The tarantulas on the plateau seem to be significantly larger than the ones I see in the Trabuco Canyon area. Coyotes are also very common on the plateau. They are used to seeing people and will generally not flee when they see you. Another common sight is raptors patrolling the hillsides for a meal. Red-tailed hawks are among the most commonly observed.

View to the southeast from near Monument Hill

Less than a mile up the trail is a spur trail to Monument Hill which provides good views of the plateau. From this viewpoint you can see the abrupt transition of the oak woodland to sage scrub and chaparral to the southeast. As you continue west on Monument Road, you'll eventually cross Ranch Road. Continue a short distance to to the Trans Preserve Trail. A left turn will take you back toward the adobes. To extend the loop hike by a couple of miles, turn right. Otherwise, head left (south) on the Trans Preserve Trail. At this point you will be in the heart of the plateau's prairie. Continue south a short distance to Hidden Valley Road, yet another former ranch road, and head to the right (west). Poppy Hill will be to your right, and in a hundred yards or so you will see an abandoned ranch site with an old, broken windmill to your left. Before you know it, you will reach Los Santos Trail for the final segment of the hike. Turn left here. This trail climbs gently uphill through oak woodlands. Once you connect with Vernal Pool Trail, your car will be a short distance to the right. Depending on when you started your hike, you may want to turn left instead and head back once more to the vernal pools. Check out how the pools appear in different light. Since there tends to be a larger number of wildflowers near the vernal pools, they may be more attractive in the afternoon light if you started your hike in the early morning. If you didn't enjoy exploring the plateau, hiking just may not be your deal.