Nine Sisters

{{Short description|Volcanic mountains and hills in California, United States}} {{Infobox mountain | name = Nine Sisters | other_name = Los Morros, Seven Sisters | image = Hills in San Luis Obispo (cropped).jpg | image_caption = Cerro Romauldo, Chumash Peak, and Bishop Peak as viewed from Laguna Lake | country = United States | subdivision1_type = State | subdivision1 = California | parent = | listing = | area_km2 = | area_ref = | borders_on = | length = {{cvt|16.6|mi|km}} | length_orientation = WNW–ESE | length_ref = | width = {{cvt|3.9|mi|km}} | width_orientation = | width_ref = | highest = Bishop Peak | elevation_m = 475 | elevation_ref = | coordinates = {{coord|35.3024744|N|120.6973949|W|type:mountain_region:US-CA_scale:100000_source:GNIS|format=dms|display=inline,title}} | coordinates_ref = <ref name="gnis">{{cite gnis |id=239356 |name=Bishop Peak |access-date=2009-06-23}}</ref> | geology = Volcanic plugs | orogeny = | age = 20–25 mya (Late Oligocene to Early Miocene) | range_coordinates = | range_coordinates_ref = | map_image = | map_caption = }} The '''Nine Sisters''' or '''the Morros''' or '''Seven Sisters''' are a chain of twenty-three, although typically only nine or seven are included, volcanic mountains and hills in western San Luis Obispo County, Southern California. They run between Morro Bay and San Luis Obispo.

==Geography== The peaks were created more than 20 million years ago during the Miocene Epoch of the Neogene Period, as volcanic plugs of magma which welled up and solidified inside softer rock which has since eroded away.{{Citation needed|date=March 2023}} Every plug, with the exception of just two, formed in a nearly straight line.

Two of the plugs are in Morro Bay State Park. The highest is Bishop Peak at {{Convert|1559|ft|m}}.

===Peaks=== The peaks in order from Morro Bay to San Luis Obispo, including their height, a sortable table.

{| class="wikitable sortable" |- !Name ! data-sort-type="number" | Height<br /><small>ft (m)</small> |- | Morro Rock | {{convert|576|ft|m|0|abbr=values}} |- | Black Hill | {{convert|665|ft|m|0|abbr=values}} |- | Cerro Cabrillo | {{convert|911|ft|m|0|abbr=values}} |- | Hollister Peak | {{convert|1404|ft|m|0|abbr=values}} |- | Cerro Romauldo | {{convert|1306|ft|m|0|abbr=values}} |- | Chumash Peak | {{convert|1257|ft|m|0|abbr=values}} |- | Bishop Peak | {{convert|1559|ft|m|0|abbr=values}} |- | Cerro San Luis Obispo | {{convert|1292|ft|m|0|abbr=values}} |- | Islay Hill | {{convert|775|ft|m|0|abbr=values}} |}

== Geology == The Nine Sisters are a chain of volcanic plugs composed predominantly of dacite. About 20 to 25 million years ago, magma welled up underneath a layer of softer rock and solidified. The softer overlying rock has since eroded away, leaving a distinct rugged shape.<ref name="SierraClub">{{cite web |url=http://santalucia.com.s39011.gridserver.com/ninesis.html |title=The Nine Sisters of San Luis Obispo County |publisher=Santa Lucia Chapter, Sierra Club |accessdate=2017-01-11 |archive-url=https://web.archive.org/web/20170214000305/http://santalucia.com.s39011.gridserver.com/ninesis.html |archive-date=2017-02-14 |url-status=dead }}</ref>

==Features== The Nine Sisters, being less accessible to human intrusions, support a wide variety of Coastal sage scrub and California oak woodlands flora, and of birds and other fauna.

Their volcanic origin makes them of significant geological interest. They are popular with photographers and rock climbers.

===Panorama=== {{Panorama|image=Image:Labeled Panorama of the 9 Sisters in San Luis Obispo, California.jpg |fullwidth=5050 |fullheight=725 |caption={{center|Panorama taken from Montaña de Oro State Park. }}|height=300}}

==References== {{Reflist}} * {{cite web | url = http://santalucia.com.s39011.gridserver.com/ninesis.html | title = The Nine Sisters of San Luis Obispo County | publisher = Sierra Club San Luis Obispo | accessdate = 2009-06-25 | archive-url = https://web.archive.org/web/20170214000305/http://santalucia.com.s39011.gridserver.com/ninesis.html | archive-date = 2017-02-14 | url-status = dead }}

==External links== * {{commons category-inline|Nine Sisters (volcanoes)}}

Category:Nine Sisters Category:Landforms of San Luis Obispo County, California Category:Volcanic plugs of California Category:Morro Bay Category:San Luis Obispo, California Category:Volcanoes of California Category:Paleogene California Category:Miocene California