It's been called America's“Wonderland”for good reason.Generations of travelers have embraced Yellowstone—the first national park in the United States—and explored its wonders,spread across some 3,471 square miles,mostly in Wyoming,but with portions(部分)in Montana and Idaho.

This unmatched wilderness, now marking 150 years as a national park,is vastand varied,consisting offorests,lakes,mountains,valleys,and canyons(峡谷).Some 90 percent of the park and its surrounding region remains in a wild state,constituting one of the last large undamaged ecosystems in the northern temperate(温带的)zone.

Yellowstone wasestablished asa national park in 1872“for the benefit and enjoyment of the people”.Its founding marked the birth of the US National Park System and represents the public wild lands known as the Greater Yellowstone Ecosystem,nearly 10 times larger than the park.

The region's geological history reaches back at least 66 million years,when volcanism(火山活动)produced spectacular features.The park includes three calderas(破火山口),formed from volcanic eruptions 2.1 million,1.3 million,and 640,000 years ago,respectively.

Indigenous Americans have lived in the region for more than 11,000 years.The ancestors used the resources of this land forfood,shelter,medicine and religious purposes for millennia.

Reading Check

1.What does Yellowstone consist of as a national park?

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2.When was Yellowstone established as a national park?

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