Named for the common camas (Camassia quamash) which profusely blooms here in April and early May, this preserve hosts more than 300 plant species.
The rocky plateau was exposed 12,000- 19,000 years ago when the Bretz Floods poured down the present Columbia River Gorge and far into the Willamette Valley. The floods swept soil and vegetation from parts of the valley and deposited granitic boulders (called "glacial erratics") from as far away as Canada.
The hills of West Linn, above the Clackamas and Willamette rivers, in Northwest Oregon
Conservancy volunteers are restoring Oregon white oak woodlands by removing invasive Douglas-fir trees. Populations of the rare white rock larkspur are monitored by Conservancy ecologists. Researchers also monitor water quality and study ways to minimize the impacts of urban development on the preserve's hydrology.
During spring and summer, volunteers lead guided hikes and teach visitors about the ecology of the preserve. Additionally, teams of volunteers work to eradicate invasive, non-native Scots broom from the grassland, and English ivy and Himalayan blackberry from the woodlands. West Linn High School ecology students use the preserve as an outdoor classroom and help keep it litter-free.
Common camas — historically a highly-valued food source of Pacific Northwest Native Americans — blooms in April and early May, creating a stunning contrast to dark basalt bedrock and green mosses. More than 300 plant species are found on the preserve, including some rare Willamette Valley species (e.g., the rare white rock larkspur occurs here and at only six other places in the world). The shallow soils of this rocky plateau support wet meadows, Oregon white oak-madrone woodlands, vernal and permanent ponds, and even a stand of quaking aspen.
The preserve provides habitat for many well-known bird species, including the wood duck, California quail, hairy woodpecker, western bluebird and golden-crowned kinglet.
The preserve is signed, with an interpretive board indicating trails. Trails are muddy in spring and the boardwalk can be very slippery. Watch out for poison oak.
Please observe the following guidelines while hiking: