Southern Oregon Coast Range

Southern Oregon Coast Range

Cow Creek, a tributary of the South Umpqua River
Highest point
Peak Bone Mountain
Coordinates 42°54′58″N 123°51′00″W / 42.91611°N 123.85000°W / 42.91611; -123.85000Coordinates: 42°54′58″N 123°51′00″W / 42.91611°N 123.85000°W / 42.91611; -123.85000
Dimensions
Length 55 mi (89 km) North-South
Geography
Southern Oregon Coast Range
Country United States
State Oregon
Parent range Oregon Coast Range
Borders on Central Oregon Coast Range and Klamath Mountains
Geology
Age of rock Paleocene and Eocene
Type of rock volcanic and forearc basin

The Southern Oregon Coast Range is the southernmost section of the Oregon Coast Range, in the Pacific Coast Ranges, located in the southwest portion of the state of Oregon, United States, roughly between the Umpqua River and the middle fork of the Coquille River, beyond which are the Klamath Mountains. To the east is the Umpqua Valley and to the west the Pacific Ocean. This approximately 55-mile (89 km)-long mountain range contains mountains as high as 3,547 feet (1,081 m) for Bone Mountain. The mountains are known locally in the Roseburg area as the Callahan Mountains, or simply as The Callahans.[1]

Geology

As with the Oregon Coast Range as a whole, the Southern Oregon Coast Range likely began as an ocean island chain that collided with the continental tectonic plate of North America more than 60 million years ago.[2] In the Southern Range the 64‑million-year-old Roseburg volcanics that formed this section are the oldest portions of the entire range.[2] The range is part of a forearc basin that has slowly rotated about 51 degrees since the Eocene period.[2] Much of the mountain structures are pillow basalt formations created during the volcanic period and then uplifted with the collision into the continental plate.[2] Other geologic features are mainly the result of erosion and weather forces carving steam beds and valleys out of the rock formations.[2]

Flora and fauna

Salal (Gaultheria shallon)

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.[3] Birds living in the Southern Coast Range include a variety of smaller and larger bird species.[4] These include northern goshawks, peregrine falcons, pileated woodpeckers, olive-sided flycatcher, and western bluebirds.[5] The northern spotted owl, listed as a threatened species by the United States also inhabit the mountain forests.[6] Aquatic life includes river lamprey, Pacific lamprey, coastal cutthroat trout, Millicoma longnose dace, Umpqua chub, red-legged frogs, southern seep salamander, western pond turtles, coho salmon, Chinook salmon, steelhead trout, and others.[5] Other wildlife includes fringed myotis bats, long-legged myotis bats, Townsend’s big-eared bat, fishers, and sharptail snakes, northern flying squirrels, red tree voles, Roosevelt elk, among others.[5][6][7] Other small animals include shrews, moles, deer mice, and ermine.[8]

Plants include large stands of Douglas-fir trees, western hemlock forests, cedar trees, with portions of these forests including old-growth stands.[6] Other flora include Sitka spruce, salmonberry, salal, tanoak, and western azalea.[9] Portions of the range are in the Elliott State Forest.

Location and climate

The range begins around the Umpqua River with the Central Oregon Coast Range to the north. Oregon Route 38 is the general divide between the two sections. On the southern end the Coquille River’s middle fork provides the general dividing line between the Central Range and the Klamath Mountains to the south and east.[2]

The climate of the mountains is of the mild maritime variety.[4] It is characterized by cool dry summers followed by mild and wet winters.[4] Most precipitation falls in the form of rain, with snow during the winter months at the higher elevations.[4] Annual precipitation varies from 60 to 120 inches (1,500 to 3,000 mm), with more in the higher elevations.[4] The average high temperature in January is 36.3 °F (2.4 °C), and the average high in July is 61.9 °F (16.6 °C) with temperature also varying by elevation.[4]

Peaks

All peaks in the range are over 3,000 feet (910 m) in elevation.

Mountain name Elevation County
feet metres
Bone Mountain[1] 3,547 1,081 Coos
Kenyon Mountain[10] 3,300 1,006 Coos
Buzzard Rock[11] 3,051 930 Douglas
Bear Mountain[12] 3,031 924 Douglas

Rivers

Map of the region with major rivers in blue. Orange line shows divide between watersheds flowing to the coast and those flowing north or east.

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

See also

References

  1. 1 2 "Bone Mountain". Geographic Names Information System. United States Geological Survey.
  2. 1 2 3 4 5 6 Orr, Elizabeth and William Orr, and Ewart Baldwin. Geology of Oregon. Kendall/Hunt Publishing, 1992, 4th edition.
  3. ↑ Field Guide to the Forested Plant Associations of the Northern Oregon Coast Range: Wildlife Habitat Relationships for the Coast Guide. (PDF) ECOSHARE. Retrieved on June 26, 2007.
  4. 1 2 3 4 5 6 McGarigal, Kevin; William C. McComb (August 1995). "Relationships Between Landscape Structure and Breeding Birds in the Oregon Coast Range". Ecological Monographs (The Ecological Society of America) 65 (3): 235–260. doi:10.2307/2937059. JSTOR 2937059.
  5. 1 2 3 Notice of intent, to conduct scoping meetings. Federal Register: May 9, 2005, pages 24450-24452. (Volume 70, Number 88). U.S. Fish and Wildlife Service. Retrieved on June 26, 2007.
  6. 1 2 3 Carey, Andrew B., Janice A. Reid, and Scott P. Horton. Spotted Owl Home Range and Habitat use in Southern Oregon Coast Range. Journal of Wildlife Management. 54(1):11-17. (PDF) U.S. Forest Service. Retrieved on June 26, 2007.
  7. ↑ G. W. Witmer, D. S. deCalesta. Habitat Use by Female Roosevelt Elk in the Oregon Coast Range. The Journal of Wildlife Management, Vol. 47, No. 4 (Oct., 1983), pp. 933-939.
  8. ↑ Aubry, Keith B., Mark J. Crites, and Stephen D. West. Regional Patterns of Small Mammal Abundance and Community Composition in Oregon and Washington. (PDF) U.S. Forest Service. Retrieved on June 26, 2007.
  9. ↑ Tarrant, Robert F. and Chris Maser. From the Forest to the Sea: A Story of Fallen Trees: Introduction. Tree Dictionary. Retrieved on June 26, 2007.
  10. ↑ "Kenyon Mountain". Geographic Names Information System. United States Geological Survey.
  11. ↑ "Buzzard Rock". Geographic Names Information System. United States Geological Survey.
  12. ↑ "Bear Mountain". Geographic Names Information System. United States Geological Survey.

External links

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