The World's Largest Bishop Pine Forest Is in Point Reyes

Everyone’s heard about the wonders of California’s coastal redwood trees. They can live for hundreds, even one or two thousand years, all while enduring West Coast fires, storms and pests.

But there’s an equally fascinating native California tree: the bishop pine. While it’s not a household name, the drought-tolerant, rocky, soil-loving plant has fashioned its own way of surviving the ages.

Bishop pines are everything that redwoods are not. They get canker infections and snap like pencils. When their root balls are soggy, a strong breeze tips them over. In a wildfire? Woosh, they’re gone.

But the fragility of the bishop pine is arguably its strength.

The largest natural bishop pine forest in the world is in Tomales Bay State Park in Point Reyes. Just like the groves of their majestic cousins, the coastal redwoods, bishop pine forests can last for thousands of years. However, it’s because each individual bishop pine can quickly make space for the next generation.

The spread of pencil trees

Bishop pines were once widespread throughout western North America. That was during the Tertiary period, over 2.5 million years ago. Now, their range is mostly limited to a sliver along California’s coast. And it’s shrinking still!

A Bishop Pine at Jepson Memorial Grove, along the Johnstone trail, at Tomales Bay State Park on August 20, 2024.

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Gina Castro

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One culprit is a fungal infection that causes bishop pines to grow cankers, which appear as large bulges in a tree’s branches and trunk. Cankers girdle a tree’s branches and trunk, causing them to bulge and leak resin. The girdle reduces the flow of nutrients, weakening the trunk so that it eventually snaps in two like a broken pencil.

There are many snapped and fallen trees in Tomales Bay State Park, as well as in Inverness, a small unincorporated community nestled between the state park and Tomales Bay.

Cleaning up after the pines

To fully appreciate the largest and oldest remaining bishop pine forests, hikers can take the Johnstone Trail in Tomales Bay State Park. There, they’ll pass through the trees and other vegetation still coated in dew from the coastal fog and walk up the low hills to views of Tomales Bay glistening in the distance — views snatched between the trunks of bishop pines now a hundred feet tall.

While hiking the trail, it’s more or less a matter of time before one runs into local Emmanuel Serriere while he’s cleaning up the tangle of trunks and branches that happen when a massive tree falls and takes down unlucky neighbors with it.

Serriere has cleared the Johnstone Trail of bishop pines and other trees for 14 years. It began when he retired next door and started walking the trail regularly. One day, the trail was blocked by a fallen tree. Instead of waiting for someone else to do something, he took his chainsaw and unblocked the trail himself.

Emmanuel Serriere clears the Johnstone Trail in Tomales Bay State Park.

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Lusen Mendel

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Serriere walks the trail almost daily for his own enjoyment, but he takes note of how to improve the experience for everyone: removing loose roots that he calls “widow makers;” filling in giant potholes left by mature root balls; and, of course, clearing fallen trunks.

The state park works with multiple volunteers and staff to keep the Johnstone Trail open and safe for visitors, but Serriere is particularly active. He enjoys the labor, and more than that, he enjoys the experience of a pleasant hike, something he’s proud to share with fellow hikers.

Serriere estimated that he’d removed over a hundred tree trunks from the Johnstone Trail. He often works with fellow volunteer Gerald Meral and coordinates with park rangers on particularly bad pile-ups.

However, you’ll know a Serriere tree removal when you see one. The evidence remains on the slowly decomposing trunks lying next to the trail — literally on each cross-section, where Serriere has recorded in big fat Sharpie the date when he cleared that particular fallen tree.

A tree lies fallen alongside the Johnstone Trail in Tomales Bay State Park. Emmanuel Serriere clears the trail as part of his maintenance work and dates the trunks with a permanent marker as a memento of his effort.

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Suited to thrive

Still, not all locals share Serriere’s disdain for the pesky bishop pines.

Tom Gaman, a professional forester who has studied the Tomales Bay bishop pine forest in detail, grows bishop pines on his property. Gaman said he likes that they’re indigenous and thrive under the right natural conditions. If they’re healthy enough, they can even overcome canker infections.

Tom Gaman beside a bishop pine he grew from seed.

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Lusen Mendel

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Gaman showed me a dozen mature bishop pines around his yard that he planted from seed.

One does not simply buy bishop pine seeds. Gaman collected the pine cones himself. Even his 5-year-old bishop pines had little cones on them. The hard part was getting the seeds out. Bishop pine cones are sealed shut with resin. The seeds stay locked in these closed cones until a fire melts the resin so the cones can finally pop open.

Bishop pine seedlings growing in Tom Gaman’s yard.

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Lusen Mendel

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Gaman extracted the seeds by roasting the cones in his oven, but wild bishop pines rely on wildfires to reproduce. Although wildfires often kill mature bishop pines, the heat also opens their cones, and the fiery winds distribute the seeds, which then regenerate into new trees.

Since bishop pines require wildfire to produce, they happily increase the risk of wildfire as they age. The grove around the Johnstone Trail is full of dead trees, fallen branches, and dense mounds of dried needles. “Around here, you can walk through a bishop pine forest, and it hasn’t burned for so long that the litter can be a foot deep,” Gaman said.

This build-up of organic material stokes fears of an exceptionally big and fast-moving wildfire ripping through Inverness. Until that happens, though, the litter is actually a big problem for the bishop pines.

Tom Gaman holds his collection of extracted bishop pine seeds. The seeds are locked inside pine cones held shut with pitch. Gaman opens the cones by roasting them in his oven. Bishop pines rely on wildfires to reproduce in the wild.

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Lusen Mendel

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Gaman said that bishop pine seeds won’t germinate unless they’re down on what foresters call “bare mineral soil.” In 1939, a dozen years before Tomales Bay State Park opened, there was a big fire that cleared the land. The bishop pine forest we see today naturally sprung back after that wildfire.

Now, the forest is 80 years old, and the dying bishop pines are being replaced by oak and bay. Without another wildfire, this indigenous bishop pine forest — the largest natural bishop pine grove in the world — will eventually disappear.

Resilience of the forest, not the trees

Gaman explained that it’s not because bishop pines are fragile. “There might be 40 generations of bishop pines in the life of one redwood tree,” Gaman said. “So bishop pines are resilient in that the young ones can burst onto the landscape after a fire.”

The beauty of bishop pines is that they make space for the next generation. While it’s a pain to clear fallen trees, it’s a chore that’s easier to appreciate after the full experience of hiking the Johnstone Trail.

Emmanuel Serriere hikes through the bishop pine forest along the Johnstone Trail in Tomales Bay State Park.

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Lusen Mendel

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After I watched Serriere clear a lower part of the trail, we hiked up to a ridge. First, he pointed out the fallen tree he’d cleared and marked with the trail’s highest altitude. Then he turned to the clearing that the dead tree exposed.

“Look, we got new babies,” Serriere exclaimed. “New bishop pines coming up.”

A Bishop Pine visible on the center left, can be seen from Heart’s Desire beach, at Tomales Bay State Park on August 20, 2024.

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Gina Castro

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