Backbone Creek Research Natural Area Establishment Record

The Backbone Creek Research Natural Area covers 430 acres (174 ha), and the elevations range from 1250 to 2400 ft (381-731 m). With the San Joaquin River as the northern boundary, the RNA consists mainly of north-facing slopes. Three intermittent streams dissect the area. The surface soil is grayish brown, slightly acid, coarse sandy loam; the subsoil is brown, strongly acid, sandy clay loam, overlying on weathered acid igneous bedrock. The annual precipitation is approximately 25 inches (6361 mm).