Our Region

Oak and prairie habitats in the Willamette Valley are some of the most iconic, culturally important, and imperiled in Oregon.

Restored open oak woodland. Credit: Long Tom Watershed Council

leaf and acorn icon

Then and Now

The First Peoples of the Willamette Valley, including the Kalapuya, have been inseparable from the landscape since time immemorial.

As the original land stewards, they used fire to maintain open conditions and nurture habitats that support hundreds of plant and animal species, many of which hold cultural importance as food, medicine, tools, weaving and home materials, decorations, essences for storytelling, and more. Prior to European colonization, approximately two million acres of prairie and oak habitat and 25,000 Kalapuyan people existed in the Willamette Valley. Early Euro-American settlers to the Valley described wide expanses of prairie interspersed with scattered oaks, maintained in an open condition by fires set by Native Americans. The last 170 years have brought dramatic change to the Valley. Settlement resulted in the conversion of many native ecosystems to urban and agricultural land use and regular burning was halted, allowing woody vegetation and conifers to move into prairies, oak savannas, and woodlands.

old detailed illustration of a landscape with two native indians in the foreground
Valley of the Willamette River painting from 1845 by Henry Warre. Credit: Oregon Historical Society.
close up of purple flowers and grass in a meadow with a large oak tree in the background and blue sky above
Garry Oak and Camas Meadow Credit: Alanah Nasadyk Creative Commons

Today

Today, it is estimated that oak habitat in the Valley is found on under ten percent of its pre-settlement area while prairie is found on less than two percent. Much of what remains is fragmented, isolated, and heavily impacted by fast-growing conifers and invasive species. Despite 170 years of loss and fragmentation, significant and timely habitat conservation opportunities are still before us.

These opportunities, if acted upon, will have essential and lasting benefits both to Oregon’s natural and human communities. Without swift action, however, this window of opportunity will close. In addition to the continued loss of biodiversity, additional oak-prairie dependent species could be added to the endangered species list, complicating conservation and creating new barriers to economic development. More importantly, we risk the loss of some of the signature features of this landscape and an important part of what has long made the Willamette Valley such a unique and special place to live.

Habitat profiles

General distribution of habitat types within the Willamette Valley based on landscape position.

Graphic by Oregon State University Extension and the Long Tom Watershed Council

Savanna & Woodland Habitat Types of the south Willamette Valley

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Brochure

Management strategies

For more guidance on how to manage oak habitats, see the Resources page.

Managing Fire-Adapted Oak Habitats in the South Willamette Valley

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Brochure

Tribal connections

Learn more about contemporary Tribes and Indigenous culture at the following sites.