 Many species of plants are found throughout the middle and upper basin , including California poppy , white alder , Oregon ash , oak , poison oak , bigleaf maple , Indian rhubarb , buttonbush , willow , whiteleaf manzanita , and historically , sugar pine , before logging began in the late 19th century . Squirrels , raccoon , jackrabbits , bats , skunks , beavers , mule deer , coyote , bobcat and black bear are among the mammal species found in the middle and upper watershed . 
