Subsection M261Er
Eastern Slopes

Lithology and Stratigraphy.   Mesozoic granitic predominate in this subsection, but there are large areas of pre-batholith sedimentary and metamorphic rocks.  Volcanic rocks are sparse; the largest exposure being Pleistocene basalt and pyroclastic rocks at Crater Mountain on the west side of Owens Valley, near Poverty Hill.   Pleistocene glacial till and outwash are common in the northern part of the subsection.  Quaternary alluvium is extensive only in Kelso and South Fork Valleys near the southern end of the Sierra Nevada.

Geomorphology.   This subsection is characterized by very steep fault-line scarp and steep mountains.  Slopes are gently sloping to moderately steep on Quaternary volcanic rocks, which are not extensive, and very gently to moderately sloping on Quaternary alluvial fans and basin floors.  Glacial erosion has modified much of the northern part of the subsection.  Cirques, aretes, cols, and horns are common there.  The rivers, except some of those in glaciated terrain,  flow through very steep sided V-shaped canyons.  The elevation ranges about 2500 to 10,000 feet.  Faulting, mass wasting and fluvial erosion are the main geomorphic processes.

Soils.  The soils are Lithic Torriorthents; Typic and shallow Xeric Torripsamments; shallow Typic Xeropsamments; Aridic, Torriorthentic, and shallow Entic Haploxerolls; shallow Typic Cryopsamments; Andic and Lithic Cryumbrepts; Typic Argixerolls; and Ultic Haploxeralfs.   Vitrandic Torriorthents are common on Crater Mountain.  Soils in Kelso and South Fork Valleys are mostly Xeric Torripsamments and Xerollic Haplargids.  The soils are mostly well drained.  Soil temperature regimes are thermic, mesic, frigid, and cryic.  Soil moisture regimes are mostly xeric on the north to aridic on the south end of the subsection.  Soils may have udic moisture regimes where snow persists through spring, melting to keep soils moist through much of the summer.

Vegetation.   The predominant natural plant communities northwest of Round Mountain are Jeffrey pine series, White fir series, Mixed subalpine forest series, and Red fir series, with Big sagebrush series at lower and communities of Subalpine meadow habitat at higher elevations. South of about Wonoga Peak, near Owens Lake, they are mainly Singleleaf pinyon series and lesser amounts of Black bush series.  Also, there are Joshua tree series, California buckwheat series, and Mixed scrub shrublands at the south end of the Sierra Nevada, and Needlegrass grasslands in South Fork Valley.

Characteristic series by lifeform include:
Grasslands: Ashy ryegrass series, Montane meadow habitat, Mountain heather - bilberry series, Nebraska sedge series, Needle-and-thread series, Rocky Mountain sedge series, Rothrock sagebrush series, Shorthair reedgrass series, Shorthair sedge series, Subalpine meadow habitat.
Shrublands: Big sagebrush series, Bitterbush series, Black bush series, California buckwheat series, Greenleaf manzanita series, Joshua tree series, Low sagebrush series, Parry rabbitbrush series, Rubber rabbitbrush series, Subalpine upland shrub habitat, Subalpine wetland shrub habitat, Tobacco brush series.
Forests and woodlands: Aspen series, Jeffrey pine series, Lodgepole pine series, Mixed subalpine forest series, Piute cypress stands, Red fir series, Singleleaf pinyon series, White fir series.