Hills in the Puget Lowland

Hills in the Puget Lowland, between the Cascades and the Olympic Mountains, including the entire Seattle metropolitan area, are generally between 350–450 feet (110–140 m) and rarely more than 500 feet (150 m) above sea level. Hills are often notable geologically and for social reasons, such as the seven hills of Seattle.

Formation

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The Puget Lowland lies between the Cascades and Olympic Mountains and once contained a plateau of glacial till not usually more than 350–450 feet (110–140 m) above sea level.[1][2][3] The plateau, "the most prominent single landform of the entire region",[4] was dissected by glacial outwash, forming present-day landforms: rivers, creeks and streams; glacial lakes such as Lake Washington; and numerous kettle lakes, and Puget Sound itself. High points on the plateau remain, most of which are a drumlin (rocky glacial debris), or a bedrock intrusion that predated glaciation. Hills above 500 feet are considered exceptional.[a]

Notable lowlands hills

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Hills are glacial deposits unless otherwise noted. King, Pierce and Snohomish Counties run up to the crest of the Cascades where their high points reside; therefore, the Cascades and attached foothills are excluded. Likewise for Thurston County in the Mount Rainier area, and Mason County's Olympic Mountains foothills.

North Sound

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Landforms north of the Tacoma Narrows (Island, King, Kitsap, Pierce and Snohomish counties)

Island County

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Whidbey Island and Camano Island are islands in Puget Sound and form the bulk of Island County.

  • Whidbey Island high point, 520–540 feet (160–160 m)[6] unnamed peak 500 meters from Naval Air Station Whidbey Island
  • Camano Island high point, 580 feet (180 m) unnamed peak, the lowest high point of any Washington county[7]

King County

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Seattle

Kitsap County

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The Blue Hills of the Kitsap Peninsula are unusual in that they are composed of basalt bedrock, not glacial till.[12]

  • Gold Mountain, 1,761 feet (537 m) (Kitsap County h.p. & city of Bremerton watershed on mountain contains city h.p.)
  • Green Mountain, 1,639 feet (500 m)

Bainbridge Island is an island in Puget Sound.

  • Toe Jam Hill, Bainbridge Island's high point, 425 feet (130 m)

Pierce County

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  • South Hill above Puyallup, 541 feet (165 m)[13]
  • Argonne Forest hills at Fort Lewis, formed of multiple layers of till deposited during Vashon glaciation; some hills may overlie drumlins from an earlier glacial phase.[14] Hills are designated critical habitat for the Northern Spotted Owl, an endangered species whose forest habitat in the Puget Lowland has been largely destroyed.[15]

Snohomish County

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South Puget Sound

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Landforms in South Puget Sound (Thurston and Mason counties)

Low mountains

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The Issaquah Alps Bellevue, Issaquah and Newcastle on the Eastside are considered part of the Cascades foothills by many authors.[b] They are basalt intrusions possibly related to the Blue Hills of the Kitsap Peninsula. Highest point Tiger Mountain summit, 3,004 feet (916 m).

The Anacortes Community Forest Lands contain several peaks over 1,000 feet (300 m) high, including the Fidalgo Island high point, 1,273-foot (388 m) Mount Erie.

Mason County's Olympic Mountains foothills are called the Satsop Hills.

See also

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Footnotes

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  1. ^ "The elevation is, with some local exceptions, less than 150 meters (500 feet) above sea level. Much of the landscape consists of rolling hills with a relief of only a few hundred feet."[5]
  2. ^ "Westernmost encroachment of the Cascades into the lowland contains exposures of preglacial bedrock marked by a series of peaks ... including Tiger and Squak mountains"[5]

References

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  1. ^ Williams 2000 p. 87
  2. ^ USDA 1952 p.5
  3. ^ Figge 2008 p. 27
  4. ^ Booth 1994.
  5. ^ a b Burns 1985, p. 54.
  6. ^ "Whidbey Island High Point, Washington". Peakbagger.com.
  7. ^ Martin 1994
  8. ^ U.S. Geological Survey Geographic Names Information System: Finn Hill, King County, Washington
  9. ^ a b c Raisz 1941
  10. ^ "Kirkland high point". Peakbagger.com. Retrieved December 15, 2016.
  11. ^ "Redmond High Point, Washington". Peakbagger.com.
  12. ^ Haeussler & Clark 2000.
  13. ^ U.S. Geological Survey Geographic Names Information System: South Hill, Pierce County, Washington
  14. ^ Fort Lewis forestry plan, p. 8
  15. ^ Fort Lewis forestry plan, p. 30
  16. ^ "Black Hill, Washington". Peakbagger.com.
  17. ^ U.S. Geological Survey Geographic Names Information System: Black Hill, Pierce County, Washington
  18. ^ "Heaton Hill, Washington". Peakbagger.com.
  19. ^ a b c DeLorme 2002 p. 62
  20. ^ U.S. Geological Survey Geographic Names Information System: Heaton Hill, Pierce County, Washington
  21. ^ "Kelly Hill, Washington". Peakbagger.com.
  22. ^ "Starr Hill, Washington". Peakbagger.com.
  23. ^ U.S. Geological Survey Geographic Names Information System: Starr Hill, Pierce County, Washington
  24. ^ "Lake Serene Hill, Washington". Peakbagger.com.
  25. ^ U.S. Geological Survey Geographic Names Information System: Clearview, Washington
  26. ^ Drost et al. 1998, p. 10

Sources

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