Californians are being asked to look a little closer at the natural world around them this week.
California Biodiversity Day 2026 begins Saturday, Sept. 5, launching nine days of hikes, wildlife observations, citizen-science projects, conservation work and other activities across the state.
The latest California State Parks announcement says nearly 200 events are scheduled statewide through Sept. 13, expanding on the California Natural Resources Agency’s announcement that described more than 100 events.
For residents of El Dorado County, the celebration has a particularly familiar backdrop: Folsom Lake and the foothills surrounding the county’s western edge.
Folsom Lake puts biodiversity close to home
Folsom Lake State Recreation Area has a direct El Dorado County connection. California State Parks identifies its Brown’s Ravine facility as being in El Dorado County, and the broader Folsom Lake recreation area extends across portions of El Dorado, Sacramento and Placer counties.
State Parks lists a Biodiversity Week Kickoff Event at Folsom Lake State Recreation Area on Sept. 5, followed by nature programming Sept. 6 and throughout the week.
The statewide celebration also highlights Folsom Lake for a biofluorescence walk, giving participants an opportunity to search for organisms that produce or reflect fluorescent colors under specialized lighting. A climate-resilience workday at the recreation area will also give volunteers an opportunity to help improve habitat by removing invasive plants.
That puts the larger statewide message into a distinctly local setting.
The oak woodlands, waterways, foothill habitats and open spaces around El Dorado County are not simply scenery. They are functioning ecosystems supporting a wide range of plants, insects, birds, mammals, fish and other organisms.
‘A richness … almost unparalleled’
California Secretary for Natural Resources Wade Crowfoot said the event is intended to encourage people to get outdoors and better understand the state’s biological resources.
“The fact is our state is one of three dozen ‘biodiversity hotspots’ in the world,” Crowfoot said.
California is home to more species of plants and animals than any other state, according to the Natural Resources Agency. California Biodiversity Day has been observed annually on Sept. 7 since it was established in 2018. The nine-day schedule surrounding the observance gives residents multiple opportunities to participate rather than limiting the celebration to a single day.
California State Parks Director Armando Quintero urged residents to use the celebration as an opportunity to visit the state’s parks.
“California Biodiversity Day gives people of all ages an opportunity to experience that richness firsthand,” Quintero said.
For El Dorado County, that invitation does not require a long drive.
Folsom Lake State Recreation Area offers hiking, biking, horseback riding, fishing, boating, camping and other outdoor activities. Brown’s Ravine, accessible from Green Valley Road, is one of the State Parks facilities located within El Dorado County.
Residents can become citizen scientists
One of the most accessible parts of this year’s celebration does not require registration for a guided hike or even a trip to a state park.
Organizers are encouraging residents to participate through iNaturalist, a citizen-science platform used to document observations of plants, animals and other organisms.
The statewide “Find 30 Species for California Biodiversity Day 2026” project asks participants to document 30 wild species between Sept. 5 and Sept. 13.
Those observations can help researchers and resource managers build a broader picture of California’s biodiversity. The resulting information also supports the state’s 30×30 Initiative, an effort to conserve 30% of California’s lands and coastal waters by 2030.
California Academy of Sciences Director of Community Science Rebecca Johnson said observations submitted through iNaturalist can provide valuable biodiversity information at a statewide scale.
“Every observation shared on iNaturalist — during California Biodiversity Day events and beyond — directly supports our efforts to protect the species and places that make our state extraordinary,” Johnson said.
For residents who regularly walk the trails, photograph wildflowers, watch birds, fish local waterways or simply spend time outdoors, that means ordinary observations can become part of a much larger scientific record.
From the foothills to the coast
The statewide schedule reaches far beyond the Sierra foothills.
Organizers have planned activities ranging from a 30-species challenge hike at Mount Tamalpais State Park and a search for biofluorescent organisms at Folsom Lake to tidepool exploration, birdwatching, habitat restoration, underwater bioblitzes, cultural programs and virtual wildlife presentations.
Virtual offerings will include wildlife programs featuring elephant seals at Hearst San Simeon State Park, beavers at Ed Z’berg Sugar Pine Point State Park and jellyfish at San Elijo State Beach.
The variety is deliberate.
California’s biodiversity stretches from the Pacific coast to the Sierra Nevada, from wetlands and tide pools to oak woodlands and high-elevation forests. The Biodiversity Day campaign is designed to make that diversity accessible to people regardless of age, experience or location.
Conservation begins at home
The organizers are also pushing a second message: appreciating biodiversity is only the first step.
California Volunteers is promoting Climate Action Counts, which encourages residents to take practical actions to help protect natural resources and communities.
California Volunteers Director Josh Fryday said service is already playing a role in habitat restoration and native-plant projects throughout California.
“On California Biodiversity Day, we celebrate the power of service to protect the places and ecosystems that make our state so extraordinary,” Fryday said.
For El Dorado County residents, that concept is familiar.
The county’s foothill landscape faces the same pressures affecting natural areas throughout California, including invasive species, wildfire, habitat loss, drought and changing climate conditions.
Biodiversity Week offers an opportunity to see those challenges at ground level — literally.
A reason to slow down and look
The most important part of the celebration may be the simplest.
Go outside.
Look beneath the oak trees. Watch the birds along a creek. Photograph a wildflower. Notice insects that normally go unseen. Learn which species are native and which ones are invasive.
Then document what you find.
California’s annual Biodiversity Day is officially observed Sept. 7, but the 2026 celebration runs Sept. 5-13, giving residents nine days to participate.
For people in El Dorado County, the state’s biodiversity is not some distant conservation issue.
It is along Green Valley Road.
It is around Folsom Lake.
It is in the oak woodlands, creeks, hillsides and backcountry that make the county distinctive.
And for the next nine days, Californians are being asked to stop, look and recognize just how much life is sharing the landscape with them.
For event schedules and locations, residents can consult the California State Parks events calendar and the state’s California Biodiversity Day information.
