Range sits on the northwest of Yilan County from Toucheng to Sanxing. The county is geographically divided into the cliffs and the plains. The Central Mountain Range sits to the south from Sanxing to Su'ao. The Upper Lanyang River is steep and the rapid current is highly erosive. Large amount of silt carried by the river have little time to settle because of the high slope of the lands where it flows out of the mountains and valleys. An alluvial fan is formed as a result of scattered sand and gravel settling down. Large amount of gravel accumulate in the shallow stream bed, creating alluvial fans that often forms into web-like pattern. The river tends to change courses after floods caused by heavy rainfall or river overflow. The Lanyang River slows down as it reaches mid and downstream where silt begins to settle. Yilan County is located in the northeastern Taiwan Island which covers an area of 2,143 km2. The longest distance from east to west is 63 km and from north to south is 74 km. From the mountain areas downwards, the land falls in altitude in the stages of mountains, alleys, alluvial plains, lowlands, swamps, sand hills and finally coastline. Yilan's Toucheng Township includes Guishan Island and Guiluan Island. The Senkaku Islands, known in Mandarin as the Diaoyu Islands, are claimed as part of the township. Government Yilan County is administered as a county of Taiwan Province. Yilan City is the county seat which houses the Yilan County Government and Yilan County Council. The county is headed by Magistrate Lin Zi-miao of the Kuomintang. Yilan is a sister city of Rockville, Maryland. Elected magistrates Chen Ding-nan (1981-1989) Yu Shyi-kun (1989-1997) Liu Shou-cheng (1997-2005) Lu Kuo-hua (2005-2009) Lin Tsung-hsien (2009-2017) Wu Tze-cheng (2017) Chen Chin-te (2017-2018) Lin Zi-miao (2018) Administrative divisions Yilan County is divided into 1 city, 3 urban townships, 6 rural townships and 2 mountain indigenous townships. Colors indicate the common language status of Formosan languages within each division. Politics Yilan County voted one Democratic Progressive Party legislator out of one seat to be in the Legislative Yuan during the 2016 Republic of China legislative election. Sister City Leawood, Kansas https://leawood.org/ Demographics and culture Population Today Han Chinese comprises the majority of the population in Yilan County. Education Education related affairs in Yilan County is governed by the Education Department of Yilan County Government. The county houses