1. Glen Alpine to Grass Lake
In Desolation Wilderness
GEL 103 Field Assignment
by: David Brent
7/14/12
2. Table of Contents
• Location
• O ver view
• Geological Background
• Soda Spring
• Roc k S amples
• California Corn Lily
• Sierra Garter Snake
• Resources
3. Location
This 5.45 mile hike into Desolation
Wilderness begins at the Glen
Alpine Trailhead near Fallen Leaf
Lake. The trail begins by following
the old road to the Glen Alpine
Springs Resort. The trail reaches
Grass Lake at its southeastern tip
and follows the southern shoreline
to the northwest. After a little ways
there will be nice views looking
over the lake to the northwest
towards the mountains, (1).
- Z & B Johnson’s Adventures
4. Overview
Before reaching the trailhead, be sure
to stop and look at the Glen Alpine
Falls. These are a beautiful set of
waterfalls dropping about sixty feet
down large dark boulders into a narrow
canyon. The creek above the falls up to
Lily Lake is also beautiful, with
numerous deep rock gorges. Three
more lesser waterfalls await along the
trail before reaching a gorgeous
viewpoint at Grass Lake for the best
waterfall of the bunch, Susie Lake Falls
(shown on the following slide), (3).
Glen Alpine Falls
6. The panorama surrounding this
gorgeous location was formed over
millions of years through geologic
activity and environmental changes.
Desolation Wilderness consists of
over 63,000 acres of beautiful
alpine forest and glacial valleys
containing lakes, rivers, hiking
trails, and tall peaks for climbing.
Desolation Wilderness has it all!
Grass lake is surrounded by
the characteristic Desolation
granite and has a pretty
cascade that tumbles down
cliffs on the west side.
7. Geological Background
• The geologic history of Lake Tahoe began nearly 400 million years ago
when a shallow sea covered the area that is now the Sierra Nevada
Mountains. For hundreds of millions of years, mud, sand, and shells
were slowly deposited on the floor of this ancient sea. The weight of
the thousands of feet of sediment combined with chemical processes
turned the mud, sand, and shells into mudstone, sandstone, and
limestone rock.
• At the same time, about 210 million years ago, the Pacific Plate (the
sea floor underneath the Pacific Ocean) crashed into the edge of the
North American Plate (the land and continental shelf of North
America) and was pushed down under the North American Plate. This
process, known as subduction, is how most volcanoes and all granitic
rock is formed, (7).
8. Extensive glaciation shaped the surface of
Desolation Wilderness. Ice sheets over 1,000
feet deep covered the western slopes and all
but the highest peaks of the Tahoe Basin
during the last ice age (over 200,000 years
ago). The sheer mass and grinding action of
the ice packs scoured out the basins where
nearly 130 lakes formed throughout the
Desolation area, (5).
Most of Desolation Wilderness clearly shows its icy heritage .
9. In 1863 Nathan Gilmore discovered Glen Alpine Springs. It was originally known as
Soda Spring because of the natural carbonation of the water. In 1884 Gilmore
developed a health spa resort here and began bottling the water and selling it, (2).
10. Rock Sample: Granite
• Granite is an intrusive igneous rock, meaning that it is composed of
formerly molten material that cooled below the surface. When molten
rock hardens before reaching the surface it cools relatively slowly, which
promotes the formation of large crystals of different minerals, giving the
rock a distinctive salt and pepper appearance.
• The Sierra granitic rocks were formed as a result of
the subduction of a denser oceanic crustal plate
beneath the western margin of the North American
plate as the two plates collided. Subduction is the
process that takes place at convergent boundaries by
which one tectonic plate moves under another
tectonic plate and sinks into the mantle as the plates
converge. The location of the subduction zone was
on the western edge of the Sierra Nevada region in
the foothills separating it from the Central Valley, (8).
11. Rock Sample: Sandstone
• The oldest rocks in the Sierra Nevada are quite a bit older than the granitic
rocks. A number of peaks in the eastern Sierra are capped by rocks that
are distinctly different than granite. Some of these rocks appear to be
metamorphosed versions of the sedimentary rocks that are common in
the Basin and Mojave regions. As the plutons of molten rock shouldered
their way to the surface, they came in contact with sedimentary rock of
the shallow Sierra sea (including sandstone, mudstone, and limestone).
• Sedimentary rocks (like sandstone) are
formed by the lithification
(cementing, compacting, and hardening)
of existing rock or even the
bones, shells, and pieces of formerly
living things in the area. Rocks are
weathered and eroded into tiny particles
which are then transported and
deposited along with other pieces of rock
called sediments, (8).
12. California Corn Lily
(Veratrum Californicum)
• A poisonous plant native to mountain meadows between 3,500 to 11,000 feet in
southwestern North America, the Sierra Nevada and Rocky Mountains, and as far
north as Washington State.
• It grows 1 to 2 meters tall, with an erect, un-branched, heavily leafy stem
resembling a corn stalk. It prefers quite moist soil, and can cover large
areas in dense stands near streams or in wet meadows.
• Many inch-wide flowers cluster along the often-branched
top of the stout stem; they have six white petals, a green
center, six stamens, and a three-branched pistil. The buds
are tight green spheres (as seen to the left).
• The heavily veined, bright green leaves can be more
than a foot long (as seen on the following slide).
• Also referred to as the “Skunk Cabbage,” (9).
14. Sierra Garter Snake
• Garter snakes have toxins in their saliva
which cab be deadly to their prey and
their bite may produce an unpleasant
reaction in humans, but they are not
considered dangerous to humans.
• They eat mainly fish and amphibians and
their larvae: including
frogs, tadpoles, and aquatic salamander
larvae.
• Northern populations have mottled
black coloring below. This mottling is not
present in southern populations.
Populations in streams draining into the
Sacramento River all lack lateral stripes.
• They are regularly found in seasonal
creeks, large mountain rivers, meadow
ponds, and small lakes, (10).
15. The Sierra Garter Snake ranges from the Pitt and Sacramento rivers south along
the Sierra Nevada Mountains to the western end of the Tehachapi Mountains.
16. Sierra Garter Snake
• There is fossil evidence, thanks to a find
in the Saharan Desert in Africa, that the
earliest snakes appeared about 130
million years ago during the early
Cretaceous period. This fossil was given
the name Lapparentophis defrenni.
Though incomplete, the fossil's
vertebrae were consistent with that
found in today's snakes.
• Most paleontologists agree that reptiles
evolved from Labrynthodonts. The
biggest evolutionary gain was the advent
of the shelled egg, or amniote. This
meant that the reptiles could lay their
eggs on land and not have to return to
the water to breed like their amphibian
ancestors, (12).
17. For a first time visitor, the network of trails can be a bit confusing. Grass Lake can be easily found if you
bare left at the junction marked "Grass Lake - Gilmore Lake". Remember to bring good trail shoes, a
camera, wildflower guide, fishing pole, and a swim suit for an exceptional outdoor experience.
18. Resources
1. "Glen Alpine to Grass Lake - Z & B Johnson's Adventures."
<https://sites.google.com/site/zbjohnsonadventures/hikes/california-nevada/glen-alpine-grass-lake>.
2. "Glen Alpine Springs • Hiking • California • HikeArizona.COM."
<http://hikearizona.com/decoder.php?ZTN=15364>.
3. "Glen Alpine Creek and Falls." Glen Alpine Falls.
<http://www.aboutlaketahoe.com/hiking/glen_alpine_falls.htm>.
4. "Desolation Wilderness in California." AllTrips: Lake Tahoe.
<http://www.alllaketahoe.com/nature/desolation_wilderness.php>.
5. "Desolation Wilderness." Desolation Wilderness - Sierra Nevada Geotourism MapGuide.
<http://www.sierranevadageotourism.org/content/desolation-wilderness/sie45201DE7F7C3C332A>.
6. "Grass Lake." Grass Lake - Sierra Nevada Geotourism MapGuide.
<http://www.sierranevadageotourism.org/content/grass-lake/sieD0B2608FB727DA281>.
7. "Lake Tahoe Facts, Natural History, & Human History." Lake Tahoe Facts.
<http://www.tahoeadventuresports.com/misc/tahoefacts.htm>.
8. "Sierra Nevada Physical Geography." Sierra Nevada.
<http://www.geog.ucsb.edu/~joel/g148_f09/readings/sierra_nevada/sierra_nevada.html>.
9. "Veratrum Californicum." Wikipedia. Wikimedia Foundation.
<http://en.wikipedia.org/wiki/Veratrum_californicum>.
10. "Thamnophis Couchii - Sierra Gartersnake." Thamnophis Couchii.
<http://www.californiaherps.com/snakes/pages/t.couchii.html>.
11. “Fossil Snake Facts." ehow.com.
<http://www.ehow.com/facts_5819776_fossil-snake.html>.
