1. Jennifer War d
Geology 103
Summer 2012
Lake Tahoe Field Assignment

2. Table of Contents
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Research Method
●
Geological History
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Location
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Map of Lake Tahoe
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Cave Rock
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Lake Tahoe Rocks
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Lake Tahoe Planets
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Lake Tahoe Fauna
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Resources

3. Research Method
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The information and photos in this assignment are from
various activities. The Cave Rock picture was taken last
summer on our way to Carson. My dad had never been! The
bear picture was taken in front of our house a couple of
months ago. A lot of these photos were taken on a walk I
went on 7/18/12. The Pinedrop photo is from my backyard.
●
The maps are from various websites. I tried to search for the
best ones!
●
I pulled information from books such as Plants of the Tahoe
Basin by Michael Graf (1999) and Moon Handbooks: Tahoe by
Ann Marie Brown (2006) and information from many different
websites.

4. Geological History
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Lake Tahoe was formed by geologic fault about 2 to 3 million
years ago (Gould, 2008).
●
There were blocks that were uplifted to create the Carson
Range on the east and the Sierra Nevada on the west (Gould,
2008).
●
Some of the highest peaks of the Lake Tahoe Basin that formed
during this process were Freel Peak at 10,891 ft, Monument
Peak at 10,067 ft (Heavenly Valley Ski Area), Pyramid Peak at
9,983 ft, and Mt. Tallac at 9,735 ft. (Gould, 2008).
●
Rain, stream and snow, filled the southern and lowest part of
the basin, forming Lake Tahoe. Lake Tahoe today is shaped and
landscaped by the glaciers during the Ice Age (Gould, 2008).

5. Picture of some of Lake Tahoe's Faults
(zoom in!)

6. Location
●
The driving distance from San Francisco to Lake Tahoe is 200
miles - around 3 hours 24 minutes or up to 4 hours 20 minutes
with traffic (http://wiki.answer s.com) .

7. Map of Lake Tahoe
●
Lake Tahoe is about 22 miles long and l2 miles wide with 72
miles of shoreline. The surface area covers 191 sq. miles (
http://www.tahoecam.com/ ).

8. Cave Rock
●
Cave Rock was once a par t of the neck of a volcanic
vent that existed about five million year s a go
(<http://www.sier r anevada geotourism.or g/content/cav
e-r ock/sieD297F2DC0D30D2CA8>).
●
3 million year s a go w hen Lake Tahoe was for med, the
lake level was hundr eds of feet higher than it is now.
T hese caves ar e car ved out of the r ock by wave
action of the lake over tens of thousands of year s
during that period
(<http://www.sier r anevada geotourism.or g/content/cav
e-r ock/sieD297F2DC0D30D2CA8>).

9. Cave Rock

10. Igneous Granite Rock
●
This rock has characteristics of phaneritic textured rock. This represents
slower cooling in the plutons (Monroe, James, and Reed Wincander. The
Changing Earth. fifth ed. n.d. 93. Print).
●
Granite rocks are about 210 million years old to Lake Tahoe (Whitney,
Stephen. The Sierra Nevada, A Sierra Club Naturalist's Guide <
http://www.tahoeadventuresports.com/misc/tahoefacts.htm>).

11. Igneous Diorite
●
You can find diorite all thr oughout Lake Tahoe. T his r ock is fine
and coar se at the same time and is composed of ma gma which has
cr ystallized. T his rock is distinctive because of it's salt and pepper
look. T his is due to the dar k fer r oma gnisn silicates and the light
pla gioclase (Monr oe, James, and Reed W incander. T he Changing
Ear th. fifth ed. n.d. 93. Print).

12. Pinedrop Plant
●
This planet has a fleshy root but is brittle at the same time. It comes from
Southern Canada and can be found in clusters from June until August (
http://en.wikipedia.org/wiki/Pterospora).
●
This plant get's it's nutrients from near by trees and John Muir said in his Sierra
Nevada Field Guide that they are “freeloaders”, referring to them getting their
nutrients from the surrounding plants and trees.

13. Tahoe Lupine
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Tahoe Lupine can gr ow from 1 foot to 3 feet (Graf, M, 1999).
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You can find it on Mount Rose at 9,000 feet, but there is a ton of it
here in Lake Tahoe (Gr af, M, 1999).
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It grows on ridges, on open, dr y slops and in the for est. It can also
be found on volcanic slopes (Graf, M, 1999).

14. Snowshoe Hare
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T his har e changes color s! He is white in the winter and brown in the
summer (Br own, A, 2006).
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He gets his name because of his snowshoe like feet (Br own, A, 2006).
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His ear s ar e 3 inches long that stand str aight up(Br own, A, 2006).
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Type: Mammal
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Diet: Herbivore
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Aver a ge life span in the wild:
1 year or less
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Size: 16 to 20 in (41.3 to 51.8 cm)
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Weight: 2 to 4 lbs (0.9 to 1.8 kg)

15. Snowshoe Hare

16. American Black Bear
●
Did you know that black bears have a mostly vegetarian diet? They
love fish, but fancy berries and vegetation Beede, Jill, 1996-2000
<http://www.tahoecountry.com/florafauna/blackbears.html>.
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Cubs are only born in January and early February.
●
Up to 30 bears can be found on a one mile stretch of river from
about June until September in Lake Tahoe Beede, Jill, 1996-2000
<http://www.tahoecountry.com/florafauna/blackbears.html>. .
●
Temporal range: Late Pliocene-Early Pleistocene to recent
<http://en.wikipedia.org/wiki/American_Black_Bear>.

17. American Black Bear

18. Douglas Squirrel aka Chickaree
●
I found these two excited chickaree's chasing each other. If you look closely,
you can see both of them. These guys are around all year and you can find
them in the trees and on the ground. They make high pitched sounds said to
sound like a bird (Brown, A, 2006).
●
The Douglas squirrel is one of several species of tree squirrels found in the
Basin <http://www.fs.usda.gov/detail/ltbmu/home/?cid=fsm9_046595>.

19. Resources
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Gould, M, 2008 <http://tahoe.usgs.gov/facts.html>
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Brown, Ann Marie. Moon Handbooks: Tahoe, 2006. Print.
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Graf, Michael. Plants of the Tahoe Basin, 1999. Print.
●
Monroe, James, and Reed Wincander. The Changing Earth.
fifth ed. N.p.: n.p., n.d. 93. Print.
●
Quesnel, Eve
<http://www.moonshineink.com/sections/mountain-
life/persistent-pinedrops>.
●
<http://wiki.answers.com/Q/What_is_the_driving_distance_fro
m_San_Francisco_to_Lake_Tahoe>.
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<http://www.aaccessmaps.com/show/map/us/ca/tahoesub>.

20. Resources Cont.
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<http://www.sier ranevadageotourism.or g/content/cave-
rock/sieD297F2DC0D30D2CA8>.
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Various Authors (2012) Retrieved from
http://www.nhptv.org/natureworks/douglassquirrel.htm
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Beede, Jill, 1996-2000.
<http://www.tahoecountry.com/florafauna/blackbears.html>.
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<http://animals.nationalgeographic.com/animals/mammals/snowshoe-hare/>.
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<http://en.wikipedia.org/wiki/American_Black_Bear>.
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<http://www.fs.usda.gov/detail/ltbmu/home/?cid=fsm9_046595>.
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Whitney, Stephen. The Sierra Nevada, A Sierra Club Naturalist's Guide
<http://www.tahoeadventuresports.com/misc/tahoefacts.htm >.