This subsection comprises the higher elevations and cooler parts of the San Bernardino Mountains. The mountains are a horst with faults and steep escarpments on the south-southwest, east-northeast, and west-northwest sides. The subsection is made up of steep and very steep mountains with narrow to rounded summits. The elevations range is from about 4000 feet up to 11,502 feet on Mount San Gorgonio. The predominant natural plant community is Ponderosa pine series. Precipitation is about 30 to 40 inches annually. Much of it is snow. All but the larger streams are dry through the summer. There have been natural lakes, but any lakes that persisted until historical times have been replaced by reservoirs.
For a more detailed description see;
Upper San Gorgonio Mountains
Lower San Gorgonio Mountains