Twenty years ago, The Nature Conservancy embarked upon a quest to safeguard this unique landscape and its rare species from suburban sprawl. Today, the Santa Rosa Plateau Ecological Reserve covers 8,300 acres and connects to Cleveland National Forest via a 3.5 mile-long lifeline for wildlife known as the Tenaja Corridor.

The Santa Rosa Plateau is a secluded refuge in the Santa Ana Mountains-a place of rare beauty and serenity that belies its location near the encroaching city: distant mesas glimpsed through fog, a moss-draped oak overlooking a shallow canyon, cumulus clouds floating over seasonal vernal pools.

Located in southwestern Riverside County, the plateau is a treasured keepsake of untrammeled Southern California. It blends the region's largest expanse of native grasslands with wetlands, coastal sage scrub, chaparral and dramatic stands of rare Engelmann oak.

Elsewhere on the plateau, tenajas, natural holes in basalt creekbeds, crisscross the landscape, holding water well into the dry season. Their presence is essential to sustaining more than 50 dwindling species of plants and animals, including California Orcutt grass, San Diego button-celery, mountain lions, burrowing owls and southwestern pond turtles.

In the early 1980s, the population of Riverside County was pushing 750,000 and increasingly, developers coveted the unfragmented landscape around the 2,000-foot-high sanctuary. Seeing it at risk, The Nature Conservancy purchased 3,100 acres in 1984 and created a preserve to protect the vernal pools and sensitive grasslands. Later that decade, a local volunteer group helped restore damaged stream banks, and the State conducted prescribed burns to keep the grasslands healthy.

In the early 1990s, a local grassroots group launched a public awareness campaign to expand the preserve and stave off development. The group's success paved the way for the Conservancy and its partners to more than double the size of the preserve, which they renamed the Santa Rosa Plateau Ecological Reserve.

To prevent the plateau from becoming an ecological island in a sea of cities, the Conservancy recently began piecing together land parcels between the plateau and nearby Cleveland National Forest. Once complete, the 3.5-mile-long Tenaja Wildlife Corridor will facilitate safety and ease of movement, especially for mountain lions and other large mammals that need wider areas to roam. Not only will the corridor help maintain genetic diversity on the plateau, it will provide an escape route for wildlife in the event of drought or fire.

Today, as the population of Riverside County pushes 1.7 million, more than half of the Santa Rosa Plateau is a protected paradise. Soon, the Conservancy will turn over its interests to the California Department of Fish and Game. Two long-term Conservancy employees will remain with the Reserve, and a Conservancy-established endowment will ensure its permanent care. Additionally, we'll continue to secure the remaining unprotected areas of the Tenaja Corridor.

The results of this tenacious 20-year effort represent what The Nature Conservancy is all about-working with communities and partners to preserve the diversity of life on Earth by protecting the land and water that plants and animals need to survive.