发布时间：2016-07-30 23:03:46 来源：听力鸭英语网
Today on our national parks journey, we head to the far western part of Texas. The landscape here is severe. The Chisos Mountains rise from the desert. The Rio Grande River cuts deep into ancient limestone rock. Cactus plants flower under the intense sun.
Welcome to Big Bend National Park.
At first sight, Big Bend seems empty of life. But, the park is home to many plants and animals. Over 450 kinds of birds can be found within the park, along with 75 mammal species and more than 50 kinds of reptiles.
The park's diversity comes from its three different ecosystems. Within the park are mountain, desert and river environments.
The Rio Grande sustains the park. The river starts high up in the Rocky Mountains. Melting mountain snow is its main source. It travels more than 3,000 kilometers on its way to the Gulf of Mexico.
The river cuts through the dry Chihuahuan Desert. Big Bend National Park contains the northernmost part of this desert. It is the second-largest desert in North America. Much of the desert is south of the border in Mexico. The Rio Grande serves as an international border between the United States and Mexico for about 1,600 kilometers. The park itself shares a border with Mexico for 189 kilometers.
The Chihuahuan Desert is the largest ecosystem in the park. Eighty percent of the park is desert. Animals like jackrabbits, roadrunner birds and mule deer live in the Chihuahuan. Many cactus and yucca species thrive. These are succulent plants. Most succulents have thick, heavy leaves that store water. Cacti store water in their stems.
High up in the park's Chisos Mountains, you will find fir and pine trees, aspens and maples. Temperatures here are much cooler than down on the desert floor.
The entire Chisos Mountain range exists within Big Bend. It is the only mountain range in the United States that is fully within a national park. Its highest mountains, Emory Peak and Lost Mine Peak, each rise more than 2,000 meters above the hot desert floor.
The woodland environment in the mountains is home to black bears, mountain lions, and gray foxes. It is also home to many kinds of birds. Visitors are drawn to the park because of its rare and unique bird species.
One of these is the Colima warbler. These small gray, yellow and red birds arrive at Big Bend in the springtime to mate and nest. Then, they return south to Mexico.
In the late summer, mountain sage flowers appear. Hummingbirds -- blue-throated, ruby-throated, magnificent, and Lucifer, and others -- seek out these flowers.
Along with its plant and animal life, the park is also rich in cultural history. Archaeological records of humans in the area go back about 10,000 years, beginning with the prehistoric Paleo-Indians.
Later on, the Chisos Indians lived here, as did the Comanche and Jumano people, and other native groups. Spanish explorers began to arrive in the area in the 1500s. They were searching for gold and fertile land. They described this land as "despoblado," or "uninhabited."
Much of what is now Big Bend National Park was Mexican territory until 1848. Mexican settlers farmed and raised animals here. In the early 1900s, many Anglo-Americans began settling in the area.
The creation of Big Bend National Park
Big Bend became a national park on June 12, 1944. It covers more than 320,000 hectares.
President Franklin D. Roosevelt established the park just one week after D-Day. That is the day American and British troops invaded Normandy, France. As America's attention centered on World War II, Roosevelt established a new national park for future generations to enjoy.
For several years before the park was created, hundreds of men worked to build roads and trails to prepare the area for visitors. They built the 11-kilometer road that leads to the Chisos Mountains Basin. A basin is a large area of the earth's surface that is lower than the area surrounding it.
Today, the basin is a popular place within the park. Visitors can stay in the Chisos Mountain Lodge there or at campgrounds. Many of the park's hiking trails begin near the basin.
One of the most popular is the Lost Mine Trail. It starts near the Chisos Mountain Lodge. The trail goes up sharply through forests of pine, juniper and oak trees.
The 8-kilometer-long hike passes by lookout points for viewing Casa Grande Peak, one of Texas's major mountains. Hikers can also enjoy a view into the park's Juniper Canyon.
More than 300,000 people visit Big Bend each year. Most come between November and April, when the weather is cooler.
A favorite way to explore the park is by boat on the Rio Grande. Many tour operators organize rafting trips.
Rafting trips take you through many kilometers of beautiful deep canyons. They may last half a day or several days. On longer trips, travelers sleep next to the river in tents.
Another way to enjoy the Rio Grande is in its many hot springs. These are places where hot water flows up from underground. The water temperature is over 40 degrees Celsius. The river's hot springs are said to have healing properties. They hold mineral salts from the earth.
Big Bend National Park has offered beauty, excitement and recreational challenge to visitors for more than 80 years. It is a true treasure of Texas, and the larger United States.
I'm Caty Weaver.
And I'm Ashley Thompson.
Ashley Thompson wrote this story for VOA Learning English with materials from the National Park Service. Caty Weaver was the editor.
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ecosystem - n. everything that exists in a particular environment
sustain - v. to provide what is needed for (something or someone) to exist, continue, etc.
thrive - v. to grow or develop successfully
range - n. a series of mountains or hills in a line
mate - v. to have sexual activity in order to produce young
hummingbird - n. a very small, brightly colored American bird that has wings which beat very fast
fertile - adj. able to support the growth of many plants
uninhabited - adj. not lived in by people
rafting - v. the activity of traveling down a river on a flat boat (called a raft)
tent - n. a portable shelter that is used outdoors, is made of cloth and is held up with poles and ropes