ON A CLEAR DAY, the trails winding through West Coyote Hills near Fullerton, California, offer a sweeping view of the mountains rising over Orange County’s suburban sprawl. Over 500 acres of open space are covered in low-growing, feathery coastal sage scrub, a native plant community that urban development is replacing. Dozens of coastal California gnatcatchers, a threatened native bird species, flit around the shrubs.
When it rains, vernal pools, or seasonal wetlands, form between the hills, supporting wildflowers and amphibians. Today, these wetlands are a rare habitat: More than 90% of California’s vernal pools have been lost to development. “I love the fact that even in this urban area, there’s an open space that is just a jewel,” said Angela Lindstrom, who lives nearby.
Until the 1990s, that jewel was…