Preferred substrates include aspen and black cottonwood. Wildlife includes Bewick's wrens that frequent the park's black cottonwood forest. Riparian areas support white alder, mockorange, western chokecherry, clematis, willows, black cottonwood, and water birch. The most distant ortholog found was Populus trichocarpa, also known as the black cottonwood tree. Deciduous species, such as trembling aspen, paper birch, and black cottonwood, are present but uncommon. Some black cottonwood is scattered among the conifers. Scattered among these conifers are deciduous trees such as bigleaf maple, black cottonwood, and willow. Other trees that sometimes dominate forest areas include black cottonwood. Along the creeks grow black cottonwood, alder and aspen. Other trees that sometimes dominate forest areas include black cottonwood and red alder. The land in this area is dominated by black cottonwood, red alder, and Douglas-fir. The only native deciduous tree which matches the conifers in size is the black cottonwood. Floodplain stands of black cottonwood ("Populus balsamifera" ssp. "trichocarpa") and white spruce occur uncommonly.