sentences:  The fact that these species normally grow in the shady understory of redwood and Douglas fir forests, has led to speculation that prior to the 5,000 year occupation of the Ohlone Indians, who likely burned off the area to promote the growth of natural food sources, that the upper San Pedro watershed may have been host to primordial conifer forests.Creek Dogwood, Arroyo Willow, Watercress, and several species of ferns are common in the middle and lower creeks.In the springtime, the meadows of the Middle Valley show off an array of wildflowers