Preserving and Protecting the Oak Trees of the Willamette Valley

By Matt Wastradowski

For thousands of years, the Willamette Valley looked far different than it does today. Rather than the iconic farmland we’re known for these days, oak savannas and woodlands once covered about 400,000 acres throughout the region—an area larger than London. These stands of oak dotted upland prairies, riparian meadows, and rolling hillsides all over the valley, creating the ideal habitats for a variety of wildlife and wildflowers.

These days, those sights are fewer and further between. The area’s Kalapuya people had tended to these oak groves since time immemorial, but European-American settlement in the mid-1800s brought a new generation of homesteaders and farmers to the Willamette Valley—emigrants who’d cut down the stately trees and plant hazelnut trees, berry patches, and (eventually) our world-famous grape vines. Today, fewer than 20,000 acres of oak trees cover the Willamette Valley, representing just 5% of historical totals.

We’re not here to quibble with the hard-working farmers who produce our best-loved exports today; after all, we love a handful of roasted hazelnuts, gooey berry pie, and flavorful glass of wine as much as the next person. But what was lost with the razing of the Oregon white oak tree? And can we ever get it back?

An ongoing (and growing) conservation program is trying to answer those questions. That program, spearheaded by the nonprofit Willamette Partnership, is the Oak Accord: a voluntary conservation agreement that helps private landowners protect, restore, and even plant new oak trees on their property. It’s a program that may change the very fabric of the Willamette Valley outdoors.

What is the History of Oak Trees in the Willamette Valley?

Before we discuss the Oak Accord, we have to head back in time, thousands of years, to an era when Oregon white oak and California black oak trees covered the Willamette Valley.

These trees were vital to the region’s Kalapuya population, who set seasonal fires to clear the undergrowth and maintain a healthy ecological balance. Those prescribed burns cleared away invasive plant species, gave native plants room to thrive, allowed the trees to grow into the regal monoliths we all love today, and helped the area’s first inhabitants spot wildlife while hunting. 

Oak trees thrived in these conditions, eventually growing to cover about 400,000 acres around the region. But oak populations began to dwindle when the Oregon Trail brought waves of European-American emigrants into the Willamette Valley throughout the mid- to late 1800s.

It didn’t help that public land managers throughout the 20th century banned prescribed burns, a move that allowed invasive plant species to move in and thrive—creating enough shade to kill a large number of oak trees, which depend on sunlight and a sparse ground cover to survive. Today, oak tree savannas and woodlands cover just a small fraction of their onetime habitat.

And the downstream effects of those shrinking numbers may change what kind of Willamette Valley ecosystems we live, work, and play in for decades to come. According to Nicole Maness (Partner, Resilient Habitat for Willamette Partnership’s work on habitat conservation), more than 200 species of fauna and flora depend on oak trees for survival—from native plants that grow at their base to squirrels and chipmunks that store nuts in their tree trunks. Some species of wildlife, such as the Fender’s blue butterfly, depend on a type of lupine that most commonly grows in oak woodlands.

And that’s where the Oak Accord comes in.

From there, landowners take the lead to protect the existing oak trees on their property. As Maness puts it, this is an easy, cost-effective effort that bears the most immediate benefits. (Planting a new oak woodland, after all, can require a time-consuming commitment of 10 years or more, with no guarantee of success.) Protection efforts might include removing invasive plant species (such as Himalayan blackberries, hawthorn plants, and English ivy) and thinning out smaller trees that might crowd and eventually overshadow oak trees

What is the Oak Accord?

The Oak Accord officially launched in March 2017 and, just more than five years later, boasts 65 signatories committed to preserving, protecting, and expanding the oak woodlands on their property; some are protecting vast oak forests, while others might try to preserve just a handful of trees. The vast majority of those signatories are Willamette Valley vineyards who recognize the importance of the oak trees—not just from an environmental perspective, but as part of the broader vineyard experience.

Maness says that, in talking to wineries, she makes a direct, easy-to-visualize case for why they should sign onto the accord. “‘What if we went on all of your websites and Photoshopped out the oaks as a rule?’” she says. “It would change the aesthetic of this place so dramatically. What if you’re driving down Highway 99 or tooling around these backroads, and there wasn’t any oak there?”

Once they’ve signed on, Willamette Partnership takes an inventory of the oak habitats on their property and offers tailored recommendations for preservation, conservation, and oak growth. “People are now part of this community—and everything little they do to protect or restore oak, the whole is greater than the sum of the parts,” Maness says.

To date, 65 signatories—mostly vineyards and a few public agencies (such as the Oregon Department of Corrections and the Oregon State University College of Forestry)—have signed onto the Oak Accord to help protect and preserve the stately trees. We’ve rounded up a few of our favorite places to check out these scenic slices of Willamette Valley history; for more ideas, see the full list of Oak Accord signatories here. Note that not all signatories make their property available to the public; be mindful of rules around accessing these lands when planning your visit.

Where Can You Experience Oak Savannas and Woodlands in the Willamette Valley?

Keeler Estate Vineyard

Keeler Estate Vineyard: Just outside Amity (and south of McMinnville), the celebrated Keeler Estate Vineyard takes all kinds of thoughtful steps to produce its wines—including the use of certified organic and biodynamic farming practices for chardonnay, pinot noir, and other grapes. Those environmentally minded efforts extend to preserving and caring for the regal Oregon white oak trees surrounding its vineyards.

Left Coast Estate

Left Coast Estate: The Salem-area winery Left Coast Estate offers plenty of outdoor seating amid a stand of stately Oregon white oak trees—and has spent several years working to restore and preserve the winery’s oak trees. Visitors can even enjoy a one-mile hike through Left Coast Estate’s oak grove. The winery was a founding member of the Oak Accord and even puts on an annual run-walk to help boost those restorative efforts.

Stoller Family Estate

Stoller Family Estate: Oak trees aside, the tasting experience at Stoller Family Estate is among the region’s most inventive. Visitors can watch high-definition drone footage of the surrounding vineyards, sit at tasting tables topped with interactive digital screens, and even hear about Stoller’s history through an augmented-reality digital “mural” behind one of the bars. The winery’s Experience Center, meanwhile, is surrounded by towering oak trees; one is adorned with an old-school tire swing and is among the most photographed winery sites anywhere in the Willamette Valley.

Baskett Slough National Wildlife Refuge

Baskett Slough National Wildlife Refuge: Just a 15-minute drive west of Salem, Baskett Slough National Wildlife Refuge hosts walking trails, observation decks, and quiet roads that afford incredible wildlife-watching opportunities. And while it’s not technically part of the Oak Accord, the refuge’s Baskett Butte, accessible via the two-mile Rich Guadagno Memorial Loop Trail, is home to oak stands that provide habitats for the rare Fender’s blue butterfly, the striking Kincaid’s lupine, and other plant and animal species. Learn more about the national wildlife refuges of the Willamette Valley.