Subsection 341Db
Pine Nut Mountains

Lithology and Stratigraphy.  The mountains contain mostly Pliocene volcanic rocks, largely andesite, and Triassic and Jurassic volcanic and sedimentary rocks.  Also, there are Mesozoic granitic and Pre-Cretaceous metasedimentary rocks and some Quaternary alluvium in the subsection.

Geomorphology.   Steep mountain slopes predominate in this subsection.  There are some gently to moderately sloping pediments and alluvial fans.  The mountains are oriented north-south.  The elevation range is from about 5000 feet up to 9005 feet on Mt. Como.  Mass wasting, fluvial erosion and deposition, and freeze-thaw are the main geomorphic processes.

Soils.  The soils are mostly Lithic Xerollic Haplargids, Aridic Haploxerolls, Aridic Argixerolls, Xerollic Haplargids, and Xerollic Paleargids.  The soils are well drained.  Soil temperature regimes are mesic at lower and frigid at higher elevations.  Soil moisture regimes are mostly aridic, bordering xeric, and some xeric.

Vegetation.   The predominant natural plant communities are Big sagebrush  series on lower mountain slopes and Singleleaf pinyon series on higher mountain slopes.  Utah juniper series occurs at intermediate elevations and some open Jeffrey pine series occurs at higher elevations.

Characteristic series by lifeform include:
Grasslands: Indian ricegrass series, Needle-and-thread series.
Shrublands: Big sagebrush series, Bitterbrush series, Low sagebrush series, Parry rabbitbrush series, Rubber rabbitbrush series.
Forests and woodlands: Curlleaf mountain-mahogany series, Jeffrey pine series, Singleleaf pinyon series, Singleleaf pinyon - Utah juniper series, Utah juniper series.

Surface Water.  Runoff is rapid.  It drains to the Carson River on the west or to the Walker River on the east side of the mountains.   Streams in the mountains are dry most of each year.  There is are no natural lakes in the subsection.