The thick grasses thrive in the deep soil of the steep slumps below you, erosion products of the summit rocks. Each season brings new color surprises - the golden grasses against the deep blue sky in summer, and the same grasses, now a silvery gray, bathed in the mists of winter. Park in spaces in front of sign. A Regional Park trail from the trailhead skirts the Castle Rock Park facilities and meets the old stagecoach road to Mt. Diablo. Pine Creek meanders through the forested meadows, and the road crosses the stream several times, requiring some careful balancing on stones in the stream.
Butterflies abound in sunlit clearings.
Raptor nests can sometimes be spotted with binoculars in the sandstone cavities of Castle Rock high above. Turn right on Regency Drive and drive to the dead end, with parking on the street beyond the last houses. An easy walk, but road is muddy in winter and early spring. The attractive environment is dominated by the view of the principal peaks of the park, rising sharply from the meadows at the base. In spring in particular, the sight of the rushing waters of Donner Creek meandering through flower-strewn emerald green grasslands is unforgettable.