- The basalt canyons in this 235-acre preserve contain remnant examples of Douglas-fir and ponderosa pine forest, as well as shrub-grassland ecosystems. Steep talus slopes, dominated by a variety of mosses and lichens, occur in patches throughout the preserve. The canyon bottoms support aspen and cottonwood trees, and a variety of shrub species, providing excellent habitat for songbirds and other wildlife. A wildfire burned through most of this preserve in 2002, but left much of the forest overstory intact while thinning out many of the smaller, younger trees.