Chapter One of "The Klamath Story" explores how geology of the Klamath Basin influenced weather, landscapes and human settlement.

1. CHAPTER SUMMARY: The Klamath Basin sits on the border be-
tween two major geologic areas. Volcanoes rise on one side of the Ba-
sin. Broken pieces of the earth’s crust are on the other side. This land-
scape has made the Klamath Basin a beautiful place to live. Our moun-
tains provide both challenges and opportunities for the people who
live here. Geology also has a big influence on weather in the Klamath
Basin.
The Klamath Story
Chapter 1
Geologic Forces Shape Our Landscape
Stukel Mountain rises more than 2,000 feet above the floor of
the Klamath Basin. Both Stukel and nearby Hogback Mountain
were created by “faults” in the earth’s crust. Other mountains
in our area are volcanoes.
Vocabulary list
 Geology
 Stratovolcano
 Shield volcano
 Basin and range
 Rain shadow
 Geothermal
MOUNTAINS RISE
Klamath Falls and most of the smaller towns in
our area are located in the Klamath RiverBa-
sin.* The word “basin” refers to the large area of
land in Southern Oregon and Northern California
where all streams flow into the Klamath River.
The Klamath Basin has many hills and moun-
tains that were shaped over a very long time. The
study of how hills, mountains, valleys and canyons
were formed is called geology.
Some of the biggest mountains in our region are
volcanoes. There are two types of volcanoes found in
our area.

2. spear points and knives.
Most of the big volcanoes in our area are on the
west side of the Klamath Basin. They are part of the
Cascade Mountain Range.
BASIN AND RANGE
Many mountains in our area were formed a dif-
Stratovolcanoes form
high peaks with eruptions of
lava, ash or gas at or near the
top. Mount Shasta is the largest
example of a stratovolcano in
our area. Mount Shasta has
been quiet for many years, but
geologists believe it is likely to
erupt again someday.
Mount McLoughlin is an-
other example of a stratovolca-
no. It has been quiet for a long
time, and is not expected to
erupt ever again. Crater Lake
was formed following the col-
lapse of a large stratovolcano
around 7,700 years ago.
Shield volcanoes also produce lava, but do
not build up high peaks. Instead, the lava flows
across the ground in repeated eruptions, layer upon
layer. Massive mounds of lava form a more rounded
mountain on the earth’s surface.
The largest shield volcano in our area is the
Medicine Lake Volcano, located about 45 miles
south of Klamath Falls. Geologists believe the
Medicine Lake Volcano has been producing lava
flows for a half-million years or more.
There’s one place where eruptions of lava from
the Medicine Lake Volcano occurred fairly recently
– as little as 1,100 years ago. That may seem like a
long time ago to us. But in the life of a volcano,
1,100 years is not long at all. The place where these
recent eruptions occurred is in the Lava Beds Na-
tional Monument. Many people come from far away
to visit the Lava Beds. People like to explore some
of the caves that were formed by flowing lava at the
Lava Beds.
The Medicine Lake shield volcano has also
produced massive amounts of obsidian, a volcanic
glass that often has very sharp edges. Obsidian was
extremely valuable to Native Americans, because
they could use the sharp rocks to make arrowheads,
Mount Shasta is one of the largest stratovolcanoes in the Cascade Mountain Range. It
is about 60 miles south of Klamath Falls. This photo was taken around 1930.
Major mountains
in the Klamath region
 Mount Harriman, elevation 7,979 feet.
 Gearhart Mountain, 8,135 feet.
 Pelican Butte, 8,036 feet.
 Hogback Mountain, 6,200 feet.
 Stukel Mountain, 6,525 feet.
 Yainax Butte, 7,222 feet.
 Walker Mountain, 7,083 feet.
 Diamond Peak, 8,744 feet.
 Mount McLoughlin, 9,495 feet.
 Mounta Shasta, 14,162 feet.

3. range province.”
There are many interesting types of rocks found
in our area. By far the most common rock in the re-
gion is basalt. Along with obsidian, other interesting
rocks in the region include opals, feldspar, pumice,
diatomite and petrified wood.
HOW’S THE WEATHER?
The many mountains we have in our area make
the Klamath Basin a beautiful place to live. Our
mountains provide lots of places to go camping,
hunting, fishing and hiking. Many people come
from other parts of the country to see our moun-
tains.
In some ways, however, our mountains make
life harder. For example, the mountains to the west
of Klamath Falls cause storms to drop most of their
moisture before reaching our area. Klamath Falls is
ferent way – when huge pieces of the earth’s surface
broke apart. Some parts of the ground rose high up in
the air, and other sank lower.
The place where a piece of earth rises is called a
mountain “range.” Hogback Mountain, just east of
Klamath Falls, is an example of a mountain formed
in this way. Other examples include Stukel Mountain
near Henley, and Modoc Rim near Chiloquin.
The place where a piece of the Earth sinks lower
is called a “basin.” In this case, the use of the word
“basin” means something slightly different. Here the
word “basin” refers to a broad flat valley located
next to a “range.” The city of Klamath Falls sits in a
basin.
This broken pattern of the Earth’s surface is
seen in many places to the east of Klamath Falls.
From an airplane, you can see range after range.
There’s always a basin sitting between each set of
ranges. Geologists call this region the “basin and
Crater Lake is not only Klamath County’s most famous tourist
attraction, but is also the deepest lake in America. It was
formed by the eruption and collapse of a volcano about 7,700
years ago.

4. CHAPTER 1 REVIEW
1. Which type of volcano do you think is more interesting, stratovolca-
noes or shield volcanoes?
2. How many mountains in our area can you name?
3. We know Klamath Falls doesn’t get much rain in most years. How
does that affect the type of plants that can grow here?
4. Think about it: Some people don’t like the cold winters we have
in the Klamath Basin. But many people are glad it never gets too hot. How
do you like the weather here?
5. Decision: It doesn’t rain very often in the Klamath Basin. We
enjoy lots of sunshine, but it’s usually very dry and the barren hills turn
brown in summer. If you had the chance, would you move someplace
where it rains more often?
situated in what’s called a “rain shadow,” meaning
we get very little of the moisture that comes off the
Pacific Ocean. As a result, we have a relatively dry
climate that makes it harder to grow crops.
Furthermore, the Klamath Basin sits at a high
elevation of about 4,100 feet above sea level. Be-
cause of this, we have cooler temperatures and a
shorter growing season than other parts of Oregon.
That makes it harder for farmers to grow crops. If
you pay attention to weather reports, you’ll notice
it’s usually about 10 degrees warmer in Medford
than it is in Klamath Falls. That’s because Medford
is at a much lower elevation, where the air stays
warmer. That means we have colder winters in the
Klamath Basin. But it also means it doesn’t get so
hot in the summer.
There’s one other thing about the geology of
our area that is important. We are lucky to have
many places where hot water is found just below
the surface of the earth. Water that comes out of the
ground hot is called geothermal water. In some
places the geothermal water comes out of the
ground at nearly 200 degrees Fahrenheit – close to
boiling! This hot water is used to heat businesses,
homes and schools. IFA Nurseries in Klamath Falls
uses geothermal energy to heat greenhouses where
millions of tree seedlings are grown every year.
As we travel around the Klamath Basin, it’s
interesting to think about how long it took for our
mountains and lakes to form, and how different life
would be for us if the ground in this area were
simply flat.
* The communities of Gilchrist and Crescent in northern
Klamath County are located in the Deschutes River Basin,
which flows into the Columbia River.