Mt. Desert Island The coast of the State of Maine is one of the most irregular in the world. A straight line running from the southernmost coastal city to the northernmost coastal city would measure about 225 miles. If you followed the coastline between these points, you would travel more than ten times as far. This irregularity is . the result of what is called a drowned coastline. ______【46】. At that time, the whole area that is now Maine was part of a mountain range that lowered above the sea. As the glacier (冰川) descended, however, it expended enormous force on those mountains, and they sank into the sea. As the mountains sank, ocean water charged over the lowest arts of the remaining land, forming a series of twisting inlets and lagoons (咸水湖) . The highest parts of the former mountain range, nearest the shore, remained as islands. ______【47】Marine fossils found here were 225 feet above sea level, indicating the level of the shoreline prior to the glacier. The 2, 500-mile-long rocky coastline of Maine keeps watch over nearly two thousand islands. Many of these islands are tiny and uninhabited, but many are home to thriving communities. Mt. Desert Island is one of the largest, most beautiful of the Maine coast islands. Measuring 16 miles by 12 miles, Mt. Desert Island was essentially formed as two distinct islands. ______【48】. For years, Mt. Desert Island, particularly its major settlement, Bar Harbor, afforded summer homes for the wealthy. Recently though, Bar Harbor has become a rapidly growing arts community as well. But the best part of the island is the unspoiled forest land known as Acadia National Park. Because the island sits on the boundary line between the temperate (温带) and sub-Arctic zones, the island supports the plants and animals of both zones as well as beach, inland , and alpine (高山 的) plants. ______【49】The establishment of Acadia National Park in 1916 means that this natural reserve will be perpetually available to all people, not just the wealthy. Visitors to Acadia may receive nature instruction from the park naturalists as well as enjoy camping, cycling, and boating. Or they may choose to spend time at the archeological museum, learning about the Stone Age inhabitants of the island. The best view on Mt. Desert Island is from the top of Cadillac Mountain. ______【50】. From the summit, you can gaze back toward the mainland or out over the Atlantic Ocean and contemplate the beauty created by a retreating glacier.