barrel and saguaro cacti in the semi desert landscape of usery mountain regional park near phoenix arizona

activities arizona barrel blue cacti cactus cactusn catuses cave cholla clouds county desert environment flora forest formations geological geology hiking landscape layers many maricopa mountain national nature near ocotillo outdoors park pass pencil phoenix plants precambrian prickly reginal regional reserve rock rocks saguaro sates scarface semi semidesert shadow shrubs spectacular such tonto trail trails united usery valley varieties vascular views vista wilderness wind with