The Middle Santiam RNA is located in the heart of the western Cascades in Linn County, Oregon. The natural area is made up of two adjacent units, a north unit (142 ha) and a south unit (295 ha), and includes three drainages tributary to the Middle Santiam River. With the exception of a few benches along the Middle Santiam River, the topography of the area is generally steep and predominantly south facing in the north unit and north facing in the south unit. Many soils in the RNA are unstable, and several scarps and slump benches, caused by mass soil movements, can be found in the south unit. The natural area lies within the Western Hemlock Zone, and most of the area is covered by old-growth forest (some stands are 450+ years old). Douglas fir (Pseudotsuga menziesii) is the dominant species in most of the north unit. Other species common to the north unit included Pacific madrone (Arbutus menziesii), sugar pine (Pinus lambertiana), creambush oceanspray (Holodiscus discolor), Pacific poison oak (Rhus diversiloba), western fescue (Festuca occidentalis), and Oregon iris (Iris tenax). Douglas fir and western hemlock (Tsuga heterophylla) co-dominate the south unit. Western red cedar (Thuja plicata) can also be found in the south unit, and Pacific silver fir (Abies amabilis) is common at higher elevations. Herbaceous species dominate the understory in moist areas, while shrubs dominate on drier sites. Pileated woodpeckers and the Federally listed spotted owl are notable birds believed to inhabit the area.

Middle Santiam RNA has a 1 ha permanent sample plot located on the river terrace in the south unit.

Township/Range/Section:

Sec. 7,8,17,18,19,20 and 29, T19S, R5E.

Latitude:

44,30N

Longitude:

122,20W

Quad Map:

Detroit (1956), Quartzville (1956), Cascadia (1955), and Echo Mountain (1955) - scale 1:62,500.

Threatened or Endangered Species:

The area north of the river was a Spotted Owl Management Area. A pair of adult northern spotted owls, as well as fledglings, have been seen in the area.

Exotic Species Present:

Plant Communities:

Old-growth Douglas fir (PSME) forest on steep and frequently unstable topography. Plant communitites to the north of the river (all but 4 are old-growth stands): western hemlock/salal, western hemlock/dwarf Oregon grape-salal, Douglas fir/salal, western hemlock/rhododendron-salal, western hemlock/dwarf Oregon grape, western hemlock/rhododendron-dwarf Oregon grape, western hemlock/rhododendron-Alaska huckleberry/bunchberry, western hemlock/rhododendron/beargrass, pacific silver fir/rhododendron/beargrass, and western hemlock/oxalis. Riparian plant communities occur along at least one of the 2nd-order streams.

Aquatic Features Present:

The Middle Santiam River divides the RNA into 2 segments - north and south. 3 complete 2nd-order stream drainages tributary to the Middle Santiam River are in the RNA.

Soils:

Vary with elevation and landform, but generally immature. Soils on the upper slopes and ridges are shallow, very stony loams derived from andesite and basalt. On gentle, more concave slopes, soils are deeper, gravelly loams derived from igneous flow rocks. Some soils at lower elevations developed from tuffs and breccias and are locally very deep, with friable silt loam horizons underlain by subsoils of silty clay loam to loam texture.

Other Physical Features:

A geomorphologically active region.

Past Disturbance History:

Other Comments:

Access by road and trail