Three Sisters
Elevation:	South Sister --- 10,363 ft (3,158 m)
Location:	Oregon, USA
Range:	Cascades
Coordinates:	44° 6′ 12.58″ N 121° 46′ 9.35″ W
Topo map:	USGS South Sister
Type:	Stratovolcano/Shield volcano cluster
Age of rock:	Quaternary
Last eruption:	1600 years ago
First ascent:
Easiest route:	hike (South Sister)

For other uses, see Three Sisters (disambiguation).

The Three Sisters are three volcanic peaks of the Cascade Range, located near the town of Sisters, Oregon. USGS photo of Three Sisters Source URL: http://vulcan. ... A topographical summit is a point on a surface which is higher in elevation than all points immediately adjacent to it. ... State nickname: Beaver State Other U.S. States Capital Salem Largest city Portland Governor Ted Kulongoski Official languages None Area 255,026 km² (9th)  - Land 248,849 km²  - Water 6,177 km² (2. ... The most general definition of mountain range is a group of mountains bordered by lowlands. ... Mount Adams in Washington state The Cascade Range is a mountainous region famous for its chain of tall volcanos called the High Cascades that run north-south along the west coast of North America from British Columbia to the Shasta Cascade area of northern California. ... This article is about longitude and latitude; see also UTM coordinate system Map of Earth showing lines of latitude (horizontally) and longitude (vertically); large version (pdf) The geographic (earth-mapping) coordinate system expresses every horizontal position on Earth by two of the three coordinates of a spherical coordinate system which... Example of a topographic map with contour lines Topographic maps, also called contour maps, topo maps or topo quads (for quadrangles), are maps that show topography, or land contours, by means of contour lines. ... The United States Geological Survey (USGS) is a scientific agency of the United States government. ... Mountains can be characterized in several ways. ... View of Mount Rainier, a stratovolcano. ... Mauna Kea, a shield volcano, on the Island of Hawai‘i with a light dusting of snow. ... See: In astrophysics and astrometry: star cluster, galaxy cluster In molecular physics and solid state physics: A collaboration of (mostly equal) atoms, halfway between molecules and crystals; see cluster (physics) In music: tone cluster In statistics: cluster sampling or cluster analysis metall cluster In economics: Porters cluster Techno cluster... The geologic time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of the Earth. ... The Quaternary Period is the geologic time period from the end of the Pliocene Epoch roughly 1. ... A volcano is a geological landform (usually a mountain) where magma (rock of the earths interior made molten or liquid by high pressure and temperature) erupts through the surface of the planet. ... In climbing, a first ascent (FA) is the first climb to reach the top of a mountain, or the first to follow a particular climbing route. ... Southern and northern Mount Everest climbing routes as seen from the International Space Station. ... There are several meanings of Three Sisters. ... A volcano is a geological landform (usually a mountain) where magma (rock of the earths interior made molten or liquid by high pressure and temperature) erupts through the surface of the planet. ... Mount Adams in Washington state The Cascade Range is a mountainous region famous for its chain of tall volcanos called the High Cascades that run north-south along the west coast of North America from British Columbia to the Shasta Cascade area of northern California. ... Sisters is a city located in Deschutes County, Oregon. ...

The North Sister is oldest, with towering rock pinnacles and brilliant glaciers. It has not erupted since the late Pleistocene. It is the most dangerous climb of the Three Sisters, due to its level of erosion, and thus rockfall. This article is about the geographical formation. ... The Pleistocene Epoch is part of the geologic timescale, usually dated as 1. ...

The Middle Sister is the smallest and most poorly studied. It is also the middle in age. No reports on its potential for eruptions can be made.

The South Sister is the youngest and tallest volcano of the trio. It last erupted about 1600 years ago. It has a well developed crater, which is covered by a glaciated lake. It is a long, steep, non-technical hike that can be easily completed in a day by reasonably-fit hikers. Popular starting points are the Green Lakes or Devil's Lake trailheads. A volcano is a geological landform (usually a mountain) where magma (rock of the earths interior made molten or liquid by high pressure and temperature) erupts through the surface of the planet. ...

In 2000, a satellite discovered that there was a deforming uplift near the South Sister. This could mean that she is awakening. It is also possible that magma involved with the deformation could stop moving towards the surface and cool underground and it is possible that it may be sometime before any eruptive activity were to occur. The type of magma involved in the uplift, the amount present and its properties would determine the nature of any eruptive activity. Activity could range from quiet emission of lava flows to more explosive and destructive eruptions. In mid-2005, it seems unlikely that any severe or catestrophic eruption would occur if an eruption were to occur in the near future. An eruption might or might not be centered at the current summit crater. A new vent or vents could open at or near the location of the uplift, and might produce lava flows, new cinder cones or other small volcanoes, or both. Activity could occur in more than one location around the volcano. 2000 is a leap year starting on Saturday of the Gregorian calendar. ... A satellite is an object that orbits another object (known as its primary). ... A tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. ... This article is about the type of molten rock. ...

At about 10 AM PST on Tuesday, 23rd March 2004, an earthquake swarm began with epicenters in the area of uplift. The hundreds of small earthquakes subsided over several days. USGS scientists had been expecting such earthquake swarms to accompany the uplift, and they are not considered precursory events to an eruption. The Pacific Standard Time Zone is a geographic region that keeps time by subtracting eight hours from Coordinated Universal Time (UTC). ... 2004 : January - February - March - April - May - June - July - August - September - October - November - December Deaths • 08 Abu Abbas • 20 Queen Juliana • 28 Peter Ustinov • 30 Alistair Cooke More March 2004 deaths Ongoing events EU Enlargement Exploration of Mars: Rovers Haiti Rebellion Israeli-Palestinian conflict Occupation of Iraq Same-sex marriage in... Global earthquake epicenters, 1963–1998. ... Global earthquake epicenters, 1963–1998. ... The United States Geological Survey (USGS) is a scientific agency of the United States government. ...

The Sisters were named Faith, Hope, and Charity by early settlers.

External links

• Maps and aerial photos
  • Topographic map from TopoZone
  • Aerial image from TerraServer-USA
  • Surrounding area map from Google Maps
  • Location in the United States from the Census Bureau