To the uninformed, they might look like giant puddles left behind by the last winter storm. But the 20 visitors gathered on the lower slopes of Sonoma Mountain on an overcast morning in early March understood they were special: vernal pools—vital features of the California landscape that harbor rare and endangered species found in few other places on Earth, including flowers that bloom in neat concentric rings.
Created by winter rains and disappearing by late spring, these distinctive seasonal wetlands occur where an impermeable layer of rock or clay underlies a low spot in the land. Their dramatic lifecycle creates a one-of-a-kind habitat for species adapted to survive both extended winter flood and complete summer drought.
At this early point in the season, the Sonoma Mountain pools are still in their “inundation” phase, with no flowers yet blooming. Amid the surrounding rock-strewn grasslands, purple-and-white Pacific hound’s tongue flowers have begun to open. But in the soil beneath the glassy water reflecting the gray sky and green oaks lie many more seeds waiting to germinate.
Over the next eight weeks, as the rains taper off and temperatures rise, the pools will slowly evaporate. By early June they will be blanketed in concentric rings of white Baker’s navarretia, purple Douglas’ mesamint, and blue-and-white dwarf downingia. Then the flowers will fade, leaving behind little more than broad depressions in a field of golden grass.
Once widespread across California, vernal pools have become incredibly rare. The Central Valley was chock-full of them, but nearly all historic valley-floor vernal pool habitat has been lost to agriculture, says Carol Witham, a leading vernal pool ecologist. Accounting for upland pools, approximately 10 percent of vernal pool habitat remains statewide, according to the California Department of Fish and Wildlife.
Development and other land-use changes still threaten some existing vernal pools, and even those protected in preserves must contend with non-native grasses, which crowd out delicate flowers and raise pool elevations through accumulated thatch, as well as climate change, which will alter precipitation patterns, promote algae growth, and accelerate late-season drying.
Fortunately, there are still a number of places where you can experience these unique ecosystems. Sonoma County offers several places to see vernal pools, both on Sonoma Mountain and within the Laguna de Santa Rosa wetlands complex. Here are some of the best places to visit vernal pools in Sonoma County and beyond this spring.
Sonoma County
Sonoma Mountain Vernal Pools property, Glen Ellen
Ownership: Sonoma Land Trust (private)
Access: Guided hike only, registration required (more to be announced soon)
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The 174-acre Sonoma Mountain Vernal Pools property, part of a wildlife corridor linking nearby Trione-Annadel State Park with Sonoma Mountain, is only accessible via guided tours hosted by the Sonoma Land Trust. There are long-term plans for expanded public access, including a section of the Bay Area Ridge Trail. The next tours are scheduled for Saturday, April 4, and Sunday, May 3.
North Sonoma Mountain Regional Park and Open Space Preserve, Santa Rosa
Ownership: Sonoma County Regional Parks (public)
Access: 7 a.m. to sunset
Address: 5297 Sonoma Mountain Rd.
Follow the North Sonoma Mountain Ridge Trail about three-quarters of a mile from the parking lot through a grove of coast redwoods, across a footbridge spanning South Fork Matanzas Creek, and gently uphill into a clearing where you’ll be rewarded with views of two vernal pools—and the foothills unfurling below.
Laguna de Santa Rosa Trail, Santa Rosa
Ownership: Sonoma County Regional Parks (public)
Access: 7 a.m. to sunset
Address: 6303 Highway 12 and 5420 Occidental Rd.
Tomodachi Park, Sebastopol
Ownership: City of Sebastopol (public)
Access: 6 a.m. to 10 p.m.
Address: 6665 Sebastopol Ave.
Earle Baum Center of the Blind, Santa Rosa
Ownership: LightHouse for the Blind and Visually Impaired (private)
Access: 8 a.m. to 5 p.m. Monday through Friday
Address: 4539 Occidental Rd.
Not far from Sonoma Mountain, additional vernal pools accessible to the public are located on the fertile Laguna de Santa Rosa, a vast yet heavily modified wetland draining central Sonoma County. The Laguna de Santa Rosa Trail, just outside Sebastopol, is a relatively flat, 1.8-mile multi-use path following the mainstem Laguna de Santa Rosa, with trailheads on both ends. Vernal pools are visible along the way, particularly in late spring when other ponds have dried.
Sarah Gordon, conservation science director of the Laguna de Santa Rosa Foundation, which works to conserve the Laguna de Santa Rosa, has studied vernal pools for more than 20 years. She was inspired to pursue this path after first encountering Laguna pools as a college student on a docent training program.
“I was fascinated by these wetlands that occurred all around us with endangered species found nowhere else in the world,” she says, “and pretty much nobody knew about them.” In her enthusiasm and desire to get closer, she admits, she may have accidentally stepped on some endangered Sebastopol meadowfoam. Don’t make the same mistake; visitors should stay on trails to avoid damaging sensitive habitat.
Italian rye and other European grasses encroach upon vernal pools across the Santa Rosa Plain, threatening the survival of endemic flowers. To give them a fighting chance, Gordon and her team grow, plant, and reseed endangered Sonoma sunshine, Burke’s goldfields, and Sebastopol meadowfoam, which begin blooming in April. They also remove invasive plants and accumulated thatch, and oversee grazing and prescribed burns.
Nearby Tomodachi Park is a small, 8.7-acre park within Sebastopol’s larger Laguna Wetlands Preserve. A short trail leads to a vernal pool meadow with large valley oaks and native plants, including rayless goldfields, stalked popcornflower, and common spikerush.
And just down the road, the Earle Baum Center of the Blind invites visitors during business hours to check in at the front desk before walking the winding 0.83-mile Vernal Pool Trail, used for mobility training for the visually impaired. Preserved and maintained in partnership with the Laguna de Santa Rosa Foundation, this eight-acre wetland complex is carefully managed with grazing cattle to control non-native grasses.
Foothills
Boggs Lake Preserve, Kelseyville
Ownership: Lake County Land Trust (private)
Access: daylight hours
Address: 6902 Harrington Flat Rd.
Loch Lomond Vernal Pool Ecological Reserve, Loch Lomond
Ownership: California Department of Fish and Wildlife (public)
Access: daylight hours
Address: 12355 Hwy 175
Vasco Caves Regional Preserve, Brentwood
Ownership: East Bay Regional Park District (public)
Access: guided tour only, registration required (spring 2026 tours already full)
Two examples of unusual upland vernal pools situated atop a volcanic ash substrate can be seen in Lake County, just south of Clear Lake. The Boggs Lake Preserve protects more than 200 acres, including its namesake “lake,” whose size fluctuates widely, and features a 0.75-mile self-guided trail and viewing platform. The nearby 13-acre Loch Lomond Vernal Pool Ecological Reserve includes a single large pool, fenced off to protect resident coyote thistle, navarretia, downingia, and spike rush. (As of mid-March, according to CDFW, the area has downed trees blocking some trails; cleanup work is scheduled for spring and summer.)
Another opportunity awaits—for the patient. The East Bay Regional Park District’s Vasco Caves Regional Preserve protects another set of unique vernal pools, here situated in sandstone and supporting endangered or threatened species such as California red-legged frogs, California tiger salamanders, and longhorn fairy shrimp. Due to the sensitivity of the habitat and other cultural resources, access is by extremely limited guided tours. Trips are already full for the spring 2026 season, but worth keeping an eye on for the future.
Central Valley
Jepson Prairie Preserve, Dixon
Ownership: Solano Land Trust (private)
Access: 9 a.m. to 5 p.m., with some areas off-limits; docent-led tours run every Saturday and Sunday from March 14 to May 10, starting at 10 a.m., registration not required
Address: 4845 Cook Ln.
Sacramento Splash property, Mather
Ownership: Sacramento Splash (private)
Access: daylight hours, with some areas off-limits; docent-led tours, registration required
Address: 4426 Excelsior Rd.
Established in 1997, Jepson Prairie Preserve holds one of the best remaining claypan vernal pool ecosystems in California. Its 1,566 acres include hundreds of small pools and many larger “playa” pools, home to federally endangered fairy and tadpole shrimp and an abundance of rare plants.
“It’s beautiful just to see the flowers, but the more you learn about how unique the ecosystem is and how many tiny little interactions there are, like the specialist pollinator bees that can each only use one particular plant, the easier it is to fall in love,” says Jasmine Westbrook-Barsukov, stewardship manager at Solano Land Trust, which owns and manages Jepson Prairie. “If you get out there at peak season,” she says, “it really does not take much to hook you.”
A half-mile, self-guided loop trail is open daily, and docent-led tours offer access to more of the property every Saturday and Sunday at 10 a.m., from mid-March through mid-May.
East of Sacramento at Mather Field, an educational nonprofit called Sacramento Splash helps manage access to another set of healthy valley-floor pools. Limited portions of the property are open to the public during daylight hours; additional areas can be explored on guided tours, which are offered four times each spring. The next tours are scheduled for Sunday, March 22, and Sunday, April 12.
