Welcome to the latest in The Frisc’s periodic column, Get Out Now!, in which we encourage readers to explore the city’s less heralded outdoor places. In previous installments, we climbed to the top of Tank Hill for panoramic views, visited the restored bay shore at Heron’s Head Park, and explored the variety of enclaves that comprise the Visitacion Valley Greenway. — Editors
On a recent drizzly, muggy Saturday morning, 15 volunteers wend their way around the base of Strawberry Hill, an island in the middle of Stow Lake that is also Golden Gate Park’s highest peak.
Andy Stone, a lead gardener for the city’s Recreation and Park Department, narrates the journey around and up the hill. He notes elms that need pruning, stops by the Queensland kauri pine that was part of the Golden Gate International Exhibition of 1939, and explains the origins of Huntington Falls, the man-made waterfall inspired by Sierran cascades and named for Collis P. Huntington, one of the Big Four railroad barons.
“That’s a really adventuresome stairway,” he says, pointing out a set of nearly vertical wooden steps. “But we’re not going to go that way today. We’re going to go the easier way.”
The easier way is still a healthy climb and ends next to the Strawberry Hill reservoir, a small pond behind a chain-link fence close to the top of the 425-foot peak. However, the volunteers aren’t there for stair-master aerobics or the city views; they’re here to help save butterflies.
The delicate insects are in dire need of rescue. Populations of the western monarch, one of the most beloved butterflies, shrank approximately 85 percent between 2017 and 2018, the Xerces Society for Invertebrate Conservation reported. Overall, monarch numbers are down 99.4 percent from the 1980s.
It’s not just monarchs. “It was a terrible — perhaps even catastrophic — butterfly year at all elevations and no, we don’t know why,” wrote Art Shapiro, a UC Davis professor and a Northern California butterfly expert, in his 2018 review of numerous populations.
Scientists point to a number of likely factors: habitat fragmentation or loss, record levels of insecticide production, and increasingly unpredictable weather patterns. But scientists also lack enough data to understand truly how dire the problem is, as Bay Nature explained this May. (A similar debate is underway over fears of a global insect die-off.)
A grim butterfly history
San Francisco, historically, has a bad rap in butterfly circles: It was the site of the first known species of butterfly to go extinct, the Xerces blue, in 1943. Since 2010, volunteers with the Strawberry Hill Butterfly Habitat Restoration Project have been meeting on the second Saturday of each month to ensure that the Xerces blue is the last butterfly to go extinct within the city.
There are relatively easy things most people can do to give butterflies a leg up: replace lawns with native gardens, put butterfly-friendly plants on patios, and dial back the insecticides, preferably to zero.
You could also go to Strawberry Hill, meet new people, and have a great time. As the group climbs, Michele Dana, a founding volunteer with the project, explains that butterflies, like bees, dragonflies, and other insects, engage in a mating behavior called hill topping, in which the males try to secure spots as close as possible to the top of a hill to lure females.
We are, she warns us, about to walk into a “butterfly bordello.”
The hill is home to various native species, including pipevine swallowtails, anise swallowtails, and western monarchs. It’s perfect real estate for butterflies but often overlooked by the city’s humans, perhaps because the views aren’t as expansive or stunning as those from Tank Hill. Or maybe it’s due to the plethora of nearby attractions in Golden Gate Park, none of which require a huff-and-puff climb.
Nevertheless, it claims a special place within the park’s 1,017 acres. In 1976, SF’s sister city Taipei provided the pagoda on the east shore, a stone’s throw from the bottom of the waterfall. A walk around the island’s lower path might afford you a glimpse of a blue heron rookery that was the first of its kind in San Francisco when the freakishly large birds established it three decades ago.
The hill’s name came from the wild strawberries that once covered its slopes and enchanted visitors with “the sweet scent of wild berries, which are particularly pleasant and intoxicating after a downpour,” the park’s website explains. Even before Stow Lake was created for the 1894 Midwinter Exposition, Strawberry Hill was called an island for the way it rose solitary from the surrounding green.
Strawberry Hill’s heyday was the late 19th century. An observatory at its peak, a gift to the city from land speculator Thomas Sweeney, provided visitors — who wound their way to the top in horse-drawn carriages — with dramatic views, now partially obscured by the island’s urban forest.
The observatory was ruined in the 1906 earthquake and never rebuilt, and the destination fell out of favor. Now the only way to the top is on foot, either by the few steep stairways or the wide, gently sloping path that spirals up. The observatory ruins still sit on the hilltop, which also boasts a peek-a-boo view of the Golden Gate Bridge.
Cow parsnip or poison hemlock?
Working earlier this month, however, the volunteers are mostly looking down, not up. For four hours, they remove German ivy, blackberry, nasturtium, poison hemlock, wild radish, mallow, fireweed, and other unwanted plants. Their goal is to make room for the species, like Hooker’s evening primrose and pipevine, that native butterflies need either for food or as places to lay their eggs.
“Sometimes gardening can be like a zen exercise: separating salt crystals from sugar crystals,” Rec and Park gardener Stone says. He points out which weeds to pull and which to leave. To the uninitiated, it can be a perplexing exercise. For instance, cow parsnip, a tall plant with blooms like lacy umbrellas, plays host to the larvae of anise swallowtails. But it looks almost identical to poison hemlock, which should be pulled. Stone reassures them that yanking a plant that should stay isn’t the end of the world.
Stone’s quip about weeding as meditation isn’t far from the truth. A Rec and Park crew watered the ground before the volunteers arrived, so most plants can be pulled almost effortlessly. Everyone quickly falls into a routine.
Some volunteers focus on eradicating all weeds in one patch, like the slope below the reservoir. Others choose one or two plants that are easy to identify, like wild mustard and nasturtium, and yank only those. Still others pick a project, like liberating a young oak tree from the blackberry and German ivy that have ensnared it.
Conversation drifts, and in seemingly no time, the paved path alongside the reservoir is littered with mounds of weeds that a Rec and Park worker will whisk away.
In this zen-like state, Strawberry Hill’s beauty rises to the surface. It’s an island — literally and figuratively — in this hectic city. It’s a place for quiet contemplation and getting up close and personal with the plants, animals, and insects that call the city home. And thanks to the regularly scheduled volunteer time, it’s a place where ordinary people can have an impact on the future of some of San Francisco’s most precarious inhabitants.
How to get to Strawberry Hill (and volunteer)
To help restore butterfly habitat, email recparkvolunteer[at]sfgov[dot]org to sign up, then meet at the Stow Lake boathouse at 10am sharp on the second Saturday of every month.
Stow Lake and Strawberry Hill are close to three of Golden Gate Park’s main arteries: John F. Kennedy Drive, Transverse Drive, and Martin Luther King Jr. Drive. Two bridges on opposite sides — roughly northeast and southwest — cross over the lake and connect Strawberry Hill to the rest of the park. There’s ample parking on the roads around the lake.
Via Muni, the 5, 5R, 7, 28, 44, and N will take you within walking distance. For those who like to bike, there are racks on the west side of the Stow Lake Boathouse.
