Possible Clues:

• California's ___ Woods National Monument
• "ABC World News Tonight" anchor David
• Naturalist on California's state quarter
• Conservationist on California's state quarter
• Naturalist on California quarters
• 1960s TV's "The Ghost and Mrs. ___"
• Man on California's state quarter
• Frank --, English writer who regularly appeared on 'Call My Bluff' 1920-98
• 'Studies in the Sierra' writer
• Conservationist on the California commemorative quarter