Metro Natural Areas

Gotter Prairie Natural Area

Category: Restoration (Metro Natural Areas).
Location: Located along the Tualatin River at the confluence of Baker and McFee creeks in Hillsboro.
Size: 120 acres (including approximately 20 acres of wetland prairie).

A short video about Gotter Prairie is available

Overview

This floodplain site was first put into agricultural use in the 1930s by the Gotter family and was used for growing a variety of crops and grazed until it was purchased by Metro in 1994 for habitat restoration. Since the purchase, Metro’s natural resources team has been working to restore the agricultural lands to historic native floodplain habitats. The land had most recently been used to grow potatoes. Metro has partnered on this restoration effort with the Tualatin Riverkeepers who have helped bring hundreds of volunteers to the site. In all, six plant communities are being restored on the property based on assessment of historic conditions. These include wetland prairie (20 acres), wetland scrub (15 acres), forested wetland (13 acres), oak savanna (22 acres), riparian woodland (23 acres), and emergent wetland (18 acres). The restoration process in the wetland prairie area has included removal of drainage ditches and tiles to restore wetland hydrology followed by site preparation work that included disking and spot herbicide application. Native seed was then broadcast onto the site. Sidalcea nelsoniana was thought to have disappeared from the Tualatin River watershed until botanists discovered it at the Gotter Prairie Natural Area. Following the discovery, Metro’s Native Plant Center volunteers and staff collected seed from the site and grew more than 500 plants. The next spring, approximately 200 of these checkermallow plants were planted in the site’s wetland prairie.

Management

The wetland prairie area is being managed on an ongoing basis to maintain diversity and control weed invasion. Regular flooding from the Tualatin River carries seed from non-native plants onto the site on a regular basis, which are controlled with spot herbicide applications as needed. Tufted hairgrass had initially become dominant in the wetland prairie area, but has been knocked back through a series of ecological burns and prolonged flooding of the area. This management approach has reduced tufted hairgrass cover and resulted in a much greater diversity of native species within the prairie. Metro scientists and local farmers have partnered to study grazing of the native grasses on the property, using cows to replicate what elk might have historically done. Metro hopes to acquire over 200 additional acres of adjacent land to expand the preserve.

Access and Contact

For more information about the preserve, contact the Metro Natural Areas Program at 503-797-1545 or naturalareas@oregonmetro.gov.