Subsection M261Ap
Forks of Salmon

Lithology and Stratigraphy.  This subsection contains a variety of Paleozoic to Jurassic metavolcanic and metasedimentary rocks, including components of ophiolitic sequences, of mostly Sawyers Bar and some Western Hayfork terranes.  The rocks were intruded by Mesozoic granitic rocks, generally quartz diorite to slightly more silicic rocks.   Paleozoic metavolcanic rocks of the Salmon Hornblende Schist and metasedimentary and metavolcanic rocks of the  Abrams Mica Schist, or Grouse Ridge Formation, occur in the southeast part of the subsection.

Geomorphology.   This is a subsection of mountains with rounded ridges, steep sides, and narrow canyons.  There are narrow floodplains and high terraces along the Salmon River and its tributaries.  The elevation range is about 1000 to 6000 feet.  Mass wasting and fluvial erosion are the main geomorphic processes.

Soils.  The soils are mostly Dystric and Dystric Lithic Xerochrepts and Ultic Haploxeralfs.  Soils on granitic rocks are mostly Typic Xerumbrepts.  Ultic Palexeralfs occur on high terraces and other stable land surfaces.  The soils are well drained.  Soil temperature regimes are mesic.  Soil moisture regimes are xeric.

Vegetation.  The predominant natural plant communities are Douglas fir series, Douglas-fir - tanoak series, Mixed conifer series and, on the east, Douglas-fir - ponderosa pine series.  Jeffrey pine series occurs on ultramafic rocks.   Canyon live oak series is common on very steep rocky slopes with stony soils.  Oregon white oak series occurs on clayey soils and south-facing slopes at the lower elevations.

Characteristic series by lifeform include:
Grasslands:  California annual grassland series,
Shrublands: Bewer oak series, Greenleaf manzanita series, Sadler oak series, Tobacco brush series, Wedgeleaf ceanothus series.
Forests and woodlands: Black oak series, Canyon live oak series, Douglas-fir series, Douglas-fir - tanoak series, Douglas-fir -  ponderosa pine series, Foothill pine series, Jeffrey pine series, Knobcone pine series, Oregon white oak series, Port Orford-cedar series, Western white pine series, White fir series.

Surface Water.  Runoff is rapid.  It drains to the Salmon River, which flows through the subsection.   The larger streams are perennial and some of the smaller streams are ephemeral.  There are no lakes in the subsection.