Where Monarchs Take Refuge

The vital role of California state parks in saving an iconic species. 

By Kathleen Ok-soo Richards

Every winter, an awe-inspiring spectacle comes to California’s state parks: thousands of brilliant orange-and-black western monarch butterflies cluster in forested groves along the Pacific Coast, seeking refuge from wind, rain, and extreme temperatures. 

These western monarchs arrive after traveling hundreds of miles from across the western United States. The other migratory monarch population in North America, which lives east of the Rockies, takes a different path and migrates to central Mexico. More than a dozen state parks in Central and Southern California provide crucial overwintering habitat to this iconic species. 

Since the 1980s, however, the western monarch population has plummeted by 95%, leaving groves that were once teeming with butterflies increasingly sparse. “They’re on a real extinction trajectory right now,” says Dena Spatz, Senior Wildlife Biologist at California State Parks. 

According to the most recent Western Monarch Count, the population of overwintering monarchs in California — once numbering in the millions — declined to just 9,119 this past winter, the second-lowest level recorded since tracking began in 1997. 

While numbers fluctuate from year to year — more than 200,000 monarchs were counted in each of the previous three winters — the long-term trend is one of steady and concerning decline. Scientists predict that if we fail to conserve overwintering habitat, there’s a greater than 99% chance western monarchs will go extinct by 2080. 

The primary threats to monarchs are habitat decline of overwintering groves, the disappearance of milkweed (the only host plant for monarch caterpillars), and pesticide use. But, Spatz says, “Climate change is likely exacerbating existing threats and the extreme population fluctuations we’re seeing right now.” 

The good news? Targeted efforts can make a difference. The question is — will we act in time?

The Importance of Overwintering 

Overwintering is an important phase in the monarch lifecycle. 

In one year, as many as five generations of monarchs are produced. Spring and summer generations live two to six weeks, but the fall generation can survive up to nine months. This “super generation” migrates to the coast to overwinter and then returns inland in the spring to lay eggs on milkweed. 

During overwintering, they enter diapause — a hibernation-like state in which their reproductive organs go dormant to conserve energy. If monarchs don’t survive overwintering, they won’t be able to produce the next generation.  

So, any disruption — habitat loss, exposure to pesticides, or extreme temperatures — can have far-reaching consequences. 

State Parks as Critical Overwintering Western Monarch Habitat 

Western monarch butterflies require a very specific microclimate when overwintering — often found within state parks. 

California State Parks manages more monarch overwintering habitat than any other land management entity, including 25% of the state’s priority monarch groves. As many as 57 sites in 34 parks have been verified as overwintering habitat. In the most recent Western Monarch Count, three of the four largest clusters were in state parks: Lighthouse Field State Beach (1,406 monarchs), Natural Bridges State Beach (1,400), and Pismo State Beach (556). 

“California State Parks is one of the most important, if not the most important, land management entity that protects monarchs,” says Spatz.

Groves of eucalyptus, pine, cypress, and oak trees provide the temperate climate, shelter from wind and freezing temperatures, and dappled sunlight that monarchs need. These sites are usually at low elevations, on sun-facing slopes, or in shallow canyons or gullies. They also get freshwater via fog and nectar from native plants nearby. 

Beyond habitat, state parks also provide opportunities to educate the public. Over 100,000 people visit Pismo State Beach every year to visit the monarch groves. “There is no other insect I can think of that’s as charismatic as a monarch butterfly,” says Spatz. 

Long-Term Restoration Meets New Climate Threats   

Preserving overwintering groves is one of the most urgent conservation priorities — and climate change is making it harder.   

According to the 2024 California State Parks Foundation report, “Building a Climate-Resilient California State Park System,” many monarch overwintering groves are at risk due to aging trees, development, pests, disease, and, increasingly, climate change. 

Wildfires fueled by drought and hotter temperatures can wipe out overwintering groves — which take years to grow back — in minutes. The devastating Palisades Fire in Los Angeles in January 2025 damaged a monarch overwintering grove in Topanga State Park. And in June, a fire at Natural Bridges destroyed 15 wind-protective trees, though much of the monarch grove was spared.  

Climate change threatens not only overwintering habitat but also monarch behavior. That’s because monarchs depend on environmental cues, including temperature, to trigger reproduction, migration, and hibernation. 

“We, as humans, are doing things to their habitat and accelerating climate change that are making the population decline,” says Randy Widera, Director of Programs at California State Parks Foundation. 

Another threat is the decline of milkweed. Monarchs lay their eggs exclusively on milkweed, the only food source for hungry monarch caterpillars. Of California’s 15 milkweed species, many are disappearing due to habitat loss and pesticide use. 

How California State Parks Foundation Supports Monarch Groves 

As the leading advocate for state parks, California State Parks Foundation plays a vital role in western monarch conservation, supporting efforts ranging from improving overwintering habitat at Lighthouse Field State Beach to advocating for reduced pesticide use and federal protection for the western monarch. 

One major investment is the funding and development of grove management plans — collaborative strategies to preserve and restore overwintering sites through actions like habitat restoration, fire risk reduction, and public education. 

So far, about a dozen management plans have been started or completed through a partnership between California State Parks and the Xerces Society. Several plans were funded by California State Parks Foundation through grants made possible by members and donors, including support for the Xerces Society’s work in the San Luis Obispo Coast District. Foundation grants also helped turn plans into action, supporting Groundswell Coastal Ecology’s enhancement of groves at Lighthouse Field and Natural Bridges state beaches and funding education and outreach through the Central Coast State Parks Association at Pismo State Beach. Efforts included planting nectar plants, installing wind shielding trees around groves, and coordinating volunteers. 

“We’ve really been this thought partner,” says Widera. “These grove management plans and this work would not be happening if we had not taken the initiative.” 

Most monarch habitat in California consists of nonnative eucalyptus, which is flammable and harmful to local ecosystems. Spatz emphasizes the need to balance short-term monarch needs — like reducing fire risk to maintain overwintering habitat — with long-term restoration goals, including transitioning to groves with native trees. 

This kind of science-based management is already paying off. At Andrew Molera State Park, over 1,000 monarchs returned to an overwintering grove after it was thinned as part of a management plan. While it’s hard to prove direct causation, Spatz says, “It is very likely that management helped.” Although that plan was funded by the Wildlife Conservation Board, it underscores the importance of developing grove management plans and putting them into action. 

Education is another key priority. Foundation-supported programs raise awareness about monarchs as a keystone species and the essential role of state parks in their survival. 

The Next Step in Western Monarch Conservation 

One of the most important steps to save western monarchs is securing federal protection. 

In December 2024, the U.S. Fish and Wildlife Service proposed listing monarchs as a threatened species and designating 4,395 acres in California as critical overwintering habitat. 

This would unlock federal funding and promote monarch conservation nationwide. “Federal protection would be a game changer to open up funding sources and protections from the federal side to support the actions we know work best,” says Spatz, adding that other funding sources will still be necessary. 

The federal proposal highlights the need to increase milkweed and nectar plant availability, protect overwintering sites, reduce the harmful effects of pesticides, and maintain public support. 

Spatz emphasizes that communities, Indigenous communities, businesses, and local governments must work together to raise awareness, restore groves, and reduce fire risk — while also maintaining the conditions monarchs need to survive. Key actions include planting nectar plants and trees, reducing pesticide use, and restoring milkweed within the monarchs’ breeding range. Pesticide education and regulation are particularly important to monarch survival. A recent study linked a mass mortality event of monarchs near an overwintering site in Pacific Grove to pesticide contamination. 

“We have the knowledge, the passion, the drive, and the expertise,” says Spatz. “We just have to get the work done.” 

Widera adds, “What we need is funding — and we need it at scale.” He hopes future state legislation will fund grove management efforts long-term. 

Ultimately, protecting monarchs isn’t just about saving a single species; it also supports broader conservation efforts. “They’re an iconic species, and also an umbrella species,” Spatz explains. “So, you end up moving from a single-species issue to a conservation action that has multispecies, if not ecosystem-level, benefits through habitat restoration.” 

Beyond their ecological role, monarchs capture our imagination. From their vivid orange-and-black coloring to their epic long-distance journeys and their delicate, graceful flying style, they’re symbols of beauty, resilience, determination, and transformation. They transcend borders, real and constructed, bringing us together in our shared love of this small but mighty winged creature. Against all odds — and with our help — they can survive. 
 

There are tangible ways anyone can support the recovery of western monarchs, including helping collect scientific data on monarch butterflies you observe. The simplest way to participate is to download the iNaturalist app, create a free account, and share pictures of monarchs and milkweed plants whenever and wherever you see them. If you want to do more, you can volunteer for a number of monarch butterfly community science projects, like the Xerces Society’s Western Monarch Count which involves surveying monarch overwintering sites in CA each fall/winter: https://westernmonarchcount.org/