 At the southeastern corner of Sanborn County Park sits Lake Ranch Reservoir, an attractive tiny mountain lake, accessible via either a steep canyon trail at the terminus of Sanborn Road, or by way of a longer, more level trail originating at Black Road.The latter trail, which sinuates high up along the flanks of Lyndon Canyon, is a lightly used trail, but extremely lush and forested; it crosses numerous small riparian zones, whose creeks tumble into the steep-sided canyon, originally formed by the San Andreas Fault.Shorter, less strenuous trails extend through the redwood stands and along creeksides within the lower reaches of Sanborn County Park.