Washington State Physiographic Features
Okanogan Highlands
The Okanogan highlands are foothills of the Rocky Mountains and are located in the
northeastern corner of Washington. The area consists of 7000-foot summits separated by glacial
valleys. The highlands are rich in minerals and ore deposits while the valleys are suitable for
farming.
Mount Saint Helens
Since 1857, Mount Saint Helens had been a 9,680 feet tall, dormant volcano. In the spring of
1980 it began to create bulges and shake with earthquakes. On May 18, 1980 an earthquake of 5
points on the Richter scale caused the North Slope to fall away and a subsequent blast of hot air
blew rocks, ash and debris out over 12 miles. The blast caused the mountain to lose 1,300 feet in
height. Today the mount saint Helens National Volcanic Monument covers over 110,00 acres
allowing the mountain to recover without interference from others. Wildlife, plants and trees
have made their reappearance.
Puget Sound
Puget sound stretches 100 mile south from Whidbey Island to the Olympia. It is connected to the
Pacific Ocean by the strait of San Juan de Fuca. The water way is home to many deep-water
ports such as Seattle, Tacoma, Everett and Port Townsend. It is the most densely populated area
of Washington. The economy relies on manufacturing such as Boeing and Paccer, computer
companies such as Microsoft and Amazon.com, and many government jobs. The average
temperature ranges from 41 in January to 66 in July with a typical rainfall of 30-40”
Cascade Mountains
The Cascades are a part of the 700 mile pacific Mountain system that stretches from Lassen Park
in California to the Fraser River in British Columbia Canada. The western slopes of the Cascades
receive an average of 100” of rain. An abundance of Douglas fir creates an economy based on
lumber while the many rivers produce hydroelectric power for the region using dams. The area
also relies more on tourism and outdoor recreation.
Blue Mountains
The Blue Mountains are named for the deep dark blue of the pine trees that covered the area. The
gentle slopes and board valleys of the Blue Mountains extend from southeastern Washington into
Oregon. The highest peak is Rock Creek Butte at 9,105 feet but the average height in the area is
about 6,500 feet. This area is home to farmer and rangers to a thriving tourist and outdoor
recreation industry.
Strait of San Juan de Fuca
The strait is a channel that connects the Pacific Ocean with e the Puget Sound. It is home to the
San Juan Islands and forms the border between the US and Canada. It is a narrow passage that is
only 11 to 17 miles wide.
Columbia Plateau
The Columbia Basin is a volcanic basalt plateau that rises 1,200 to 2,500 feet about sea level and
covers most of Eastern Washington. The Columbia River and its tributaries such as the Snake,
Yakima, and Spokane Rivers cut the plateau. Multiple dams have provided irrigation to this
otherwise dry area and created a productive farming environment. The average temperature in
the basin is 25˚ - 30˚ in January; 70˚ - 75˚ in July.
Columbia River
At 1,240 miles long, the Columbia River is the largest river in North America to drain into the
Pacific Ocean. It is the firs deepwater harbor north of San Francisco. Its headwaters and first 500
miles are in British Columbia. Some dams along its route are the Grand Coulee, Priest Rapids,
Wanapum, and Bonneville. It provides 1/3 of Potential US hydropower.
Olympic Mountains
Located on the Olympic Peninsula, the Olympic Mountains are home to over 60 glaciers and a
great variety of trees such as Douglas fir, Sitka spruce, Western red cedar, big leaf maple and
Western hemlock. Because of the rain shadow effect, the western Olympics receive an average
of 160” of rain in places. This abundance of rain causes some of the trees to grow over 300 feet
tall with diameters of as big as 7 feet. Olympic National Park was created in 1938 preserving
some of these tree specimens. The highest point is Mount Olympus at 7,965 feet.
San Juan Islands
The San Juan Islands are part of a submerged (underwater) mountain chain and create part of the
border between the US and Canada. Tourism and fishing are the main industry with popular
daily outings to watch for resident Orca whale pods. There are more than 170 islands and the
total population is a little over 14,000. Ferry service provides public transportation to the largest
islands including Orcas, San Juan, and Lopez.
Yakima River
The Yakima River rises in the Cascades and runs for about 200 miles before emptying into the
Columbia. It irrigates over 460,000 acres of farmland and orchards.
Mount Rainier
Originally called Mount Tahoma by local tribes, Mount Rainier stands 14,411 feet tall. It is the
tallest mountain in Washington and is part of the Cascade Range. Holding 41 glaciers, it is the
largest single mountain glacier system in the US, outside of the Alaska. A dormant volcano, it
covers 100 square miles to the southeast of the Puget Sound and can be seen on both sides of the
Cascades. Its lower slopes are covered with coniferous trees while higher up is home to alpine
meadows, waterfalls, and lakes. It was first climbed on August 17, 1870.
Snake River
The Snake River is the largest tributary of the Columbia. It begins in Yellowstone at an elevation
of 10,000 feet, wanders 1,040 miles, and drops 300 feet above sea level before meeting with the
Columbia. It cuts the deepest river gorge in North America (1 miles deep) through Hells Canyon.
The Snake forms part of the Oregon-Idaho and the Washington – Idaho borders and is a major
provider of hydroelectric power and irrigation water.
Willapa Bay
Willapa Bay is located on the southwestern coast of Washington. It is separated from the Pacific
Ocean by a 25-mile strip of land called Long Beach. The bay is the delta of the Willapa River
and home to a thriving oyster bed
Lake Chelan
Lake Chelan is located on the eastern side of the Cascade Mountains. It is 55 miles long and
extends down glacier-carved Stehekin Valley. At 1486 feet deep, it is the third deepest lake in
the US. It is heavily visited at the southern end of the lake where the town of Lake Chelan is
located. The northern part of the lake was designated a National Recreation Area in 1968.
Mount Baker
Mount Baker is located 80 miles north of Seattle in the Cascade Mountain Range. It reaches a
height of 10,781 feet. It is an active, steaming volcano but its last eruption was in 1870. it has
the second largest glacial system (after Mt. Rainier) in the US, outside of Alaska. Because of its
large glaciers and heavy snowfall (over 600 inches of snow annually), Mt. Baker is great place
to ski and snowboard.
Palouse Hills
These rolling hills provide much of WA’s productive wheat-farming land. They are home to
Pullman, site of Washington State University. These hills are located in the southeastern part of
the state, just north of the Blue Mountains.
Pacific Ocean
The Pacific is the largest of the Earth’s oceans encompassing 63,800,000 square miles and
ranging from Antarctica to the Bering Strait. It is the deepest at the Mariana’s Trench, which is
36,201 feet deep. It averages 14,040 feet in depth.
Hoh Rain Forest
The Hoh Rain Forest is located on the western side of the Olympic Mountains. It is a temperate
forest with rainfall ranging from 140 to 170 inches every year. It is home to large Sitka spruce
and Western hemlock that grow to 300 feet tall and 23 feet around. The trees are draped with
epiphytes, plants that take their nutrients from the air not from the tree or the earth. The forest is
also home to more than 100 species of plants and over 10 species of tree.
Grays Harbor
Grays Harbor is Washington’s primary Pacific Ocean sea port. This fishing port is formed by the
Chehalis, Wishkah, and Hoquiam Rivers and marks the southern boundary of the Olympic
Peninsula. The Port of Grays Harbor welcomes cruise ships and cargo ships.