Rocky Lane and his horse Black Jack must protect the gold which drought bedeviled ranchers have raised to build a dam from bad guy Smiling Jim. Rocky Lane and his horse Black Jack must protect the gold which drought bedeviled ranchers have raised to build a dam from bad guy Smiling Jim. Rocky Lane and his horse Black Jack must protect the gold which drought bedeviled ranchers have raised to build a dam from bad guy Smiling Jim. Rocky Lane and his horse Black Jack must protect the gold which drought bedeviled ranchers have raised to build a dam from bad guy Smiling Jim.