Britannica Student Encyclopedia - 2010

Nebraska and South Dakota.

Wyoming is a state of high mountains

and vast plains. The Rocky Mountains

cover the western two thirds of the state.

The Rockies are made up of several

ranges separated by wide valleys and

basins. The flat grasslands of the Great

Plains cover easternWyoming. The climate

is dry, with cold winters and warm

summers.

People

Wyoming has the smallest population of

all the 50 states. Non-Hispanic whites

make up almost 90 percent of the population.

About 6 percent of the people are

Hispanic. Native Americans make up

more than 2 percent of the population.

The Snake River and the Teton Range are

attractions of Wyoming’s Grand Teton

National Park.

BRITANNICA STUDENT ENCYCLOPEDIA Wyoming 79

 

Wyoming’s African American and Asian

populations are very small.

Economy

Mining isWyoming’s most important

industry. The state produces a lot of

coal, natural gas, and oil. Other mining

products include the clay called bentonite

and the mineral trona, which is

used to make soap and glass.

Almost all the agricultural land inWyoming

is used for ranching. Cattle and

sheep are the most valuable livestock.

The main crops include wheat, oats,

barley, hay, corn, sugar beets, beans, and

potatoes.

Tourism is also important toWyoming’s

economy. Millions of people visit the

state each year to enjoy its national

parks, including Yellowstone and Grand

Teton National Park. Popular tourist

activities include camping, fishing,

hunting, and hiking, as well as skiing

and other winter sports.Wyoming’s

cowboy culture is another tourist attraction.

The world’s largest rodeo is held

each summer in Cheyenne during a

festival called Frontier Days.

History

The Shoshone, the Arapaho, and other

tribes lived in theWyoming area when

white explorers arrived in the 1700s.

The United States bought most of the

region from France in the Louisiana

Purchase of 1803. In about 1807 John

Colter, a member of the Lewis and

Clark Expedition, explored the Yellowstone

Park area. FortWilliam (later

called Fort Laramie) was built in the

southeast in 1834. It was the first lasting

settlement in what is nowWyoming.

The cross-country railroad reached

Cheyenne in 1867. The railroad encouraged

settlers to come toWyoming. A

year later the U.S. Congress created the

Wyoming Territory. White settlement

was limited to southernWyoming until

1876, when the local Native Americans

were defeated.Wyoming became a state

in 1890.

Ranching developed intoWyoming’s

main industry in the late 1800s. For a

while the availability of vast ranches and

farmland drew people toWyoming.

During the 1900s mining replaced

ranching as the most important part of

the economy. In the 1980s the oil industry

suffered, and many people lost their

jobs.Wyoming’s population fell as

people left the state to look for work.

But between 1990 and 2000 the state’s

population again began to grow.

..More to explore

Cheyenne • Rocky Mountains

Two cowboys appear in a rodeo in Cody,

Wyoming.

Facts About

WYOMING

Flag

Population

(2000 census)

493,782—rank,

50th state; (2008

estimate)

532,668—rank,

50th state

Capital

Cheyenne

Area

97,814 sq mi

(253,336 sq

km)—rank, 10th

state

Statehood

July 10, 1890

Motto

Equal Rights

State bird

Meadowlark

State flower

Indian paintbrush

80 Wyoming BRITANNICA STUDENT ENCYCLOPEDIA

 

X-rays are powerful waves of

energy that can travel through

substances that light cannot.

(See X-rays.)

Xx

 

X-rays

X-rays are powerful waves of energy.

Like light, X-rays are a form of radiation.

They are very useful because they

can go through substances that light

cannot. X-rays can show images, or pictures,

of the inside of an object, such as

a suitcase or the human body.

How X-raysWork

An X-ray machine makes X-rays and

directs them toward an object. The

X-rays pass through some parts of the

object but are blocked by other parts.

For example, X-rays directed at a body

pass through the skin and soft tissues,

such as muscle. But hard body parts,

such as bones, block the X-rays. Special

film behind the body captures the image

made by the X-rays. When the film is

developed, the hard parts appear white

on the film. The soft parts appear black.

Medical Uses

X-rays are an important tool in medicine

and dentistry. Doctors use X-rays to

find diseases such as cancer and to study

broken bones. Dentists use them to spot

cavities in teeth.

X-rays can damage or destroy the body’s

cells. To protect the patient, the parts of

the body that are outside the area being

examined are shielded from the X-rays.

But the damaging effects of X-rays can

be useful, too. Doctors sometimes use

X-rays to kill cancerous growths.

Other Uses

X-rays also have many uses outside of

medicine. Scientists use X-rays to study

the structure of many things, both living

and nonliving. Special X-ray telescopes

pick up X-rays given off by objects in

outer space, such as distant stars. Manufacturers

use X-rays to find hidden flaws

in products. At airports, security equipment

uses X-rays to look for hidden

weapons in the baggage of travelers.

#More to explore

Dentistry • Medicine • Radiation

• Telescope

In a “positive” X-ray image the black and

white areas are reversed, so bones look dark.