Central Oregon Coast Range

Geology

The underlying rock of the Central Coast Range are the igneous rocks from the Siletz River Volcanics of the Paleocene age. It is estimated that this rock formation is up to 16 mi thick. This is the Cascadia subduction zone that has experienced uplift for several million years. Currently it is part of a large forearc basin that extends for much of the entire Coast Range on a north–south alignment. Much of the landscape is dominated by steep slopes and drainages that are deeply cut into the hillsides from the erosion. Unlike many areas in North America, the mountain range did not see glaciations during the Pleistocene age.

Flora and fauna

The Oregon Coast Range is home to over 50 mammals, 100 species of birds, and nearly 30 reptiles or amphibians that spent a significant portion of their life cycle in the mountains.

Birds living in the Central Coast Range include a variety of smaller and larger bird species.{{cite journal These include winter wrens, chestnut-backed chickadees, red-breasted nuthatches, varied thrushes, several swallow species, red crossbills, evening grosbeaks, brown creepers, olive-sided flycatchers, Hammond's flycatchers, gray jays, western wood-pewees, and western tanagers. These birds build nests from 6 to 9 in in diameter out of moss.

The central coast range is also home to some larger animals such as deer, elk, bobcat, and bear. Bear are black bear while deer are mule and black-tailed deer species. Some additional mammals are mountain beaver, coyote, mink, river otter, mountain lion, the common raccoon, common porcupine, brush rabbit, and skunk.

The coast range is inhabited by eleven different species of bats, and they account for nearly 20% of all the mammal species in the range. Species of bats include the Yuma myotis, silver-haired bat, big brown bat, hoary bat, and the long-eared myotis.

Amphibians include, but are not limited to, rough-skinned newts, northwestern salamanders, western red-backed salamander, Coastal tailed frog, Coastal giant salamander, red-legged frog, southern torrent salamander, and Ensatina.

A large section of the range is covered by the Siuslaw National Forest. Most of the range is forested and mainly within the western hemlock vegetation zone with the overstory of the forest dominated by red alder, western hemlock, western cedar, bigleaf maple, and Douglas-fir trees. The understory of the forest areas contain vine maple, Oregon grape, salmonberry, huckleberry, and sword fern to name a few. Additionally, various grass, sedge, and moss species are some of the other plant life growing in the mountain range.

Arthropods include various spiders, millipedes, collembolans, beetles, and a variety of centipedes.

Location and climate

The range begins around the Salmon River with the Northern Oregon Coast Range to the north. Oregon Route 18 is the general divide between the two sections. On the southern end the Umpqua River and Oregon Route 38 provide the general dividing line between the Central and Southern Oregon Coast Range.

The climate of the mountains is of the mild maritime variety. It is characterized by cool dry summers followed by mild and wet winters. Most precipitation falls in the form of rain, with snow during the winter months at the higher elevations. Annual precipitation varies from 60 to, with more in the higher elevations. The average high temperature in January is 36.3 °F, and the average high in July is 61.9 °F with temperature also varying by elevation.

Peaks

All peaks in the range over 3000 ft in elevation.

Rivers

The following rivers have portions of their headwaters in the Central Oregon Coast Range:

Drains to Willamette River:

• Long Tom River
• Luckiamute River
• Marys River

Drains to Pacific Ocean:

• Alsea River
• D River
• Little Nestucca River
• Salmon River
• Siletz River
• Siltcoos River
• Siuslaw River
• Smith River
• Umpqua River
• Yachats River
• Yaquina River

References

References

1. "Central Oregon Coast Range".
2. "Regional Geologic Setting". Portland State University.
3. These formations consist mainly of [[pillow basalt]], large [[lava]] flows, [[tuff breccia]], and sills. This part of the mountains are approximately 50 to 60 million years old. It is theorized that the source of these lava flows came from oceanic islands that formed over a tectonic hotspot. The entire Oregon Coast Range overlies a convergent tectonic margin that interacts with the [[Juan de Fuca Plate]] that is being sub-ducted beneath the North America tectonic plate.[http://www.wou.edu/las/natsci_math/geology/luckiamute/Appendix%20A%20Geology%20of%20Luckiamute%20River%20Watershed.pdf Geology of the Luckiamute River Watershed, Upper Willamette Basin, Polk and Benton Counties, Oregon.] Western Oregon University. Retrieved on February 29, 2008.
4. Kobor, Jeremiah S.. (2004). "Systematic variation of bedrock channel gradients in the central Oregon Coast Range: implications for rock uplift and shallow landsliding". University of Oregon.
5. [http://www.reo.gov/ecoshare/Publications/documents/FieldGuides/Coast/Coast%20Wildlife.pdf Northwest Forest Plan: Wildlife Habitat Relationships for the Coast Guide.] {{webarchive. link. (2007-09-27 ECOSHARE: Interagency Clearinghouse of Ecological Information. Retrieved on February 29, 2008.)
6. Some of the larger species in the range include the red-breasted sapsucker, common ravens, peregrine falcons, the [[pileated woodpecker]], turkey vultures, wood duck, common nighthawks, and the red-tailed hawk. Birds in lower numbers include Vaux's swifts, the endangered [[spotted owl]], bald eagles, the downy woodpecker, hairy woodpeckers, the pine siskin, the [[hermit warbler]], Pacific-slope flycatchers, golden-crowned kinglets, and ruffed grouse. One of the more common avian wildlife is the American dipper, which live mainly near rivers and streams.Anthony, Robert G. [http://goliath.ecnext.com/coms2/gi_0199-5975035/Nest-site-selection-and-productivity.html Nest-site selection and productivity of American Dippers in the Oregon Coast Range. (09-01-2006)] Goliath. Retrieved on February 29, 2008.
7. Kerr, Andy. (January 7, 1980). "Last Stand for Oregon's Coast Range". Not Man Apart.
8. John P. Hayes, Patrick T. Hounihan, Stephen P. Cross. [http://www.cope.hmsc.orst.edu/projects/bats.htm Habitat relationships and riparian-zone associations of bats in managed coast range forests.] {{Webarchive. link. (2007-06-17 Adaptive C.O.P.E. Program. Retrieved on February 29, 2008.)
9. link. (June 10, 2011 Washington State University. Retrieved on February 29, 2008.)
10. Additional species include northwestern garter snake, northern alligator lizard, [[Pacific tree frog]], western pond turtles, gopher snake, ringneck snake, and western fence lizards. Fish species in the Central Coast Range include chinook salmon, steelhead, cutthroat trout, and the threatened species [[coho salmon]].[http://www.fs.fed.us/r6/fishing/forests/gofishing/siu_streams.html Siuslaw National Forest - Stream & River Fishing.] United States Forest Service. Retrieved on February 29, 2008.