Benton County, Oregon
Benton County's Jackson-Frazier Wetland – Details
Located northeast of Corvallis at the north end of Lancaster Street, the wetland was established as a Benton County Park in 1992 to protect the natural features of the area and allow for education, research and public use. The 144 acre wetland is administered by Benton County Parks with the assistance of the Jackson-Frazier Wetland Advisory Committee. The Jackson-Frazier Wetland Management Plan is available online. (The yellow line in the photo below is the boardwalk)
Return to Jackson-Frazier Park Page
Wetland Habitat and Biota
Over a period of thousands of years the waters of Jackson and Frazier Creeks draining from McDonald State Forest have carried fine silts and clays depositing them over a coarser silt layer dating to glacial times. The resulting clay-rich wetland soils shrink and crack in our dry summers, and in winter cracks swell shut and drainage is impeded. Ponding is common throughout the wetland from mid-November to mid-June. Water in creeks and remnant drainage ditches may be high. In some years the wetland dries out in May while in others it is still soggy in July. Our understanding of the hydrological and geological history of the Jackson-Frazier Wetland has been enhanced by the work of Dave d'Amore who has recently analyzed the wetland soil history and hydrology.
Jackson-Frazier supports several wetland types including palustrine emergent wetland (wet prairie), shrub-scrub wetland, forested wetland, and emergent marsh (cattails). Each wetland type is comprised of several plant communities, which have been mapped by John Marshall. Shrubs (especially rose and hawthorn) and trees (Oregon ash) have progressively invaded wetland prairie since cattle were removed from the wetland in the early 1960s. These invaders and alien reed canarygrass pose serious management problems.
In the past, fire and grazing held the shrubs and trees at bay. There are over 300 species of flowering plants, including several rare ones, among them federally listed Bradshaw lomatium and Nelson checkermallow. Dr. Richard Halse has updated a plant list for the wetland.
Visit the USDA Plant site for photos and detailed information about many of these plants.
Jackson-Frazier serves as a diverse wet green island within the sea of the more developed Willamette Valley landscape; consequently the wetland provides an important refuge for birds of which more than 70 have been identified. Mallard, Red-tailed hawk, Virginia rail, Sora, Black-capped chickadee, and Marsh wren are common residents.
Hendrick Herlyn has compiled a bird list with reference to habitat type. It is also available in Adobe PDF format as a black and white Bird Brochure and as a color Bird Poster. Common mammals in the wetland include deer, raccoon, beaver, and nutria. There is no site-specific animal list.
For an online auditory treat, listen to John Cooney's Natural World (1/11/01) from KLCC radio.
While listening to John Cooney, treat yourself to photographs taken at Jackson-Frazier by Denise W. Ross Photography.
Facilities and Plans
Benton County Parks Department received funding for the project from EPA Region X, U.S. Fish and Wildlife Service, State Parks, several foundations and from over 100 citizens.
A two-thirds of a mile wooden boardwalk designed by Aron Faegre, a Portland architect, was completed in 1998 with the assistance of youth crews from the Community Services Consortium and numerous volunteers.
The boardwalk winds through the wetland allowing visitors to see many plant communities and habitats. There are several interpretive signs along the way. The walkway accommodates individuals with disabilities.
Peter Hammerquist installed several benches along the boardwalk for an Eagle Scout project.
Return to Jackson-Frazier Park Page
The Benton County Natural Areas and Parks Department serves the interests and pursuits of Benton County residents by providing access to natural, historic, and recreational areas and conserving, restoring and developing parkland investments.
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