Transcript Geology

The Geology of the
Bear Creek Watershed
Emigrant Lake & Bear Creek watershed
Photo by Brandon Goldman
The Bear Creek Watershed Virtual Tours
were created with funds provided by the
Bear Creek Watershed Education Partners
through a grant from the
Oregon Watershed Enhancement Board
with additional funding from Oregon Trout’s Healthy Waters Institute.
THANKS TO:
•Terri Eubanks
•Brandon Goldman
•Gerald Jones
•Chris Larson
Geology of the Bear Creek Watershed
Our area has a unique geologic history
Bear Creek watershed
Geology is the study of the earth, including
the rocks of which it is comprised, its fossilized life forms,
and the changes that happen to the earth.
Rocks and crystals, landslides, and floods
are all part of the earth’s geologic processes.
Mt. McLoughlin
Our watershed is
unique and has a
history that goes back
millions of years.
The geology that
created the
watershed helps
determine what life
forms live there.
The land and geology in our region was formed
in many places and in many different ways.
Some of the rocks were made by volcanoes; some of the rocks were formed
from slow moving and slow cooling magma that rose to form granite;
some rocks were part of the earth’s crust that was scraped to form mountains
as the continental plate moved.
In the Bear Creek watershed,
two different mountain ranges,
the Cascade and KlamathSiskiyou, come together.
Different rock and soil types create our
watershed. The colors in this map are only a few
of the defined types in Oregon. Within any one of
these types on this map are many others.
The Siskiyou Mountains have some of the highest diversity of
animal and plant species in the United States. The reason for
this is the meeting of several ecological and climate zones
and geologic types creating many different kinds of habitats
for animals and plants to live in.
Northern Spotted Owl adult & young
Photo by Chris Larson
Underlying formations in the region include
granite that rose close to the earth’s surface,
lava from ancient volcanoes that once flowed
over the lands, and sedimentary rock from long
ago seas.
Mt. McLoughlin
Rock types of the Bear Creek Watershed
Our watershed is filled with many familiar geographic
features; some of these features include the
mountains that define our watershed.
Mountains are built in two ways.
One way is through volcanic activity
when magma rises as a result of
subduction along a plate collision boundary.
The other way mountains are formed is
as a result of the piling up of crust material
along collision boundaries.
Pilot Rock is the
remnant of a long ago
lava flow.
When a volcano explodes, hot molten rock
from deep within the earth is released
and added to land above.
Subduction occurs when one
tectonic plate collides with
another forcing it under the
other, breaking up the land and
thrusting it upwards.
The Coast Range
was created this way.
Mountains and ridges
define watershed boundaries.
Ostrich
Peak
A Ridgeline View would include
Starting north and west of the mouth traveling south
around the headwaters to the east and traveling north back to the mouth
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John’s Peak @ 2806’
Miller Mtn. @ 3722’
Nelson Mtn. @ 3589’
Anderson Butte @ 5197’
Point Mtn. @ 5128’
Bald Mtn. @ 5528’
Panther Peak @ 4866’
Ostrich Peak @ 4663’
Wagner Butte @ 7418’
Mt. Ashland @ 7533’
Siskiyou Summit @ 4530’
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Pilot Rock @ 5908’
Soda Mtn. @ 6089’
Green Springs Summit @ 4618’
Green Springs Mtn. @ 5229’
Buck Point @ 4470’
Major Mtn. @ 3385’
Tom Spring Mtn. @ 5192’
Pompadour Bluff @ 2439’
Grizzly Peak @ 5920’
Tombstone @ 3214’
Roxy Ann Peak @ 3573
Much of the land surrounding the
towns of the Bear Creek watershed
is managed by
two federal agencies –
the Bureau of Land Management
and the
US Forest Service.
The Cascade-Siskiyou National Monument is a federally protected area
covering approximately 52,940 acres and includes part of the Bear
Creek watershed. Designated in 2000 by President Bill Clinton, this
area is the nation's first monument designated in recognition of an
area's biological diversity.
View of Pilot Rock
Cascade-Siskiyou National Monument
• One of the most diverse
ecosystems found in the
Cascade Range
• 200 species of birds are
known to exist in the
monument including some
threatened and
endangered species such
as the Great Grey Owl and
Peregrine Falcon
• Managing Agency- Bureau
of Land Management
John’s Peak
• Located- 10 miles West of
Jacksonville
• 2,806 feet in elevation with
over 14,000 acres of trails
with varying degrees of
difficulty
• Primary Use- All-Terrain
Vehicle (ATV) Recreation;
Class I, II, and III
• Managing Agency- Bureau of
Land Management in
conjunction with the
Motorcycles Riders
Association
Anderson Butte
• Managing Agency- Bureau of Land
Management
• Location- Klamath Mountain
Ecoregion
• Site Specifics- include a mix of
shrub land and forests dominated
by ceanothus-manzanita brush
fields and shrub oak habitat
• Outstanding Features- highly
important to a very specific bird
community that includes Blue-gray
Gnatcatcher, Wrentit, Oak
Titmouse, and the California
Towhee
Rufous Hummingbird
Wagner Butte
• Location- Towers directly above
the Bear Creek Valley southwest
of Ashland in the Rogue River
National Forest
• 7,418 feet in elevation
• Consists of miles of hiking trails
featuring panoramic views of
the Rogue and Little Applegate
Valleys
• Managing Agency- US Forest
Service
• History- former site of a Forest
Service lookout originally built
in the 1920’s, destroyed and
another built in 1961 and
destroyed ten years later
Mount Ashland
• Located- nearly due south
of the City of Ashland
• Highest point in the
Siskiyou Mountain Range
at 7,533 feet in elevation
• Managing Agency- United
States Forest Service
• Location of Mt. Ashland
Ski Area consisting of 23
runs covering 200 acres of
land accessed by four
chairlifts
• Receives an average of
300 inches of snowfall per
year
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Pacific Crest Trail skirts
the south and east sides
of the mountain
Siskiyou Summit
• Location- A mountain pass
in the Siskiyou Mountains
just north of the California
border, traversed by
Interstate- 5
• 4,530 feet in elevation
• Oregon Department of
takes photographs for
interpreting road
conditions and safety
Pilot Rock
• Located- in the Klamath/
Siskiyou Mountains near
Jackson County’s border with
California within the CascadeSiskiyou National Monument
• Remnant of a 30-million-yearold lava flow that fractured into
hexagonal columns of basalt
from which the land
surrounding has eroded away
• Native Americans called this
formation “Tants-atseniphta”
which means “Stone Stand Up”
• Managing Agency- Bureau of
Land Management
Soda Mountain
• Located- within the CascadeSiskiyou National Monument
• Houses a lookout station
originally built in 1933
• Managing Agency- Bureau of
Land Management
• Contains a highly botanical
diversity of tree species
including Douglas-fir, Ponderosa
and Sugar Pine, Incense Cedar,
mountain Mahogany, Juniper,
and Oregon White and
California Black Oak
• Draws an average of 115
different butterfly species
including the rare Checkerspot
and Klamath Mardon Skipper
Pompadour Bluff
• Location- just slightly
south east of Ashland
• Part of the Payne Cliff
formation, a sedimentary
formation comprised
primarily of
conglomerate and
sandstone
Grizzly Peak
View from Grizzly Peak
• History- Named in honor of a
famous grizzly bear called
“Old Reelfoot” for which the
Ashland High School
Football Team is named.
• Many wildflowers including
white trillium and yellow
violets are common
• Managing Agency- US Forest
Service
• Remnant of an active
volcano of 23 million years
ago
• 5,920 feet in elevation
Photo by Gerald
Jones
Roxy Ann Peak
• History- Named for Roxy Ann Bowen; wife of John B.
Bowen, a couple who settled at the base in the 1850’s
• This peak was a famous place to study birds in the 1960’s
When you are in the Bear Creek watershed
look to see some of the features and boundaries
that make up our watershed.
View from Grizzly Peak
Photo by Gerald
Jones