Crowley's Ridge is an unusual geological formation that rises up from 250 to 500 feet above the Mississippi River delta's alluvial plain in a 150 mile line from southeastern Missouri to the Mississippi River near Helena, Arkansas. It is the most prominent feature in the Mississippi Delta between Cape Girardeau, Missouri and the Gulf of Mexico. This narrow rolling hill region rising above the flat delta is the sixth, and smallest, natural division of the State of Arkansas. Most of the major cities of the Arkansas delta region lie along Crowley's Ridge.
The ridge is primarily composed of windblown soil known as loess. The formation is thought to have originally been an island between the Mississippi River and Ohio River that became a long low hilly formation after the rivers changed course millions of years ago. Some recent research questions this assumption and posits a link between the ridge and the nearby New Madrid Fault Zone.
The flora and fauna of the ridge seems more closely related to the Tennessee hills to the east than the Ozark Mountains to the west. This unique habitat has resulted in the establishment of several State and city parks, a national forest, recreational lakes, and the nation's newest scenic byway.
Crowley's Ridge received its name from, Benjamin Crowley, the first settler to reach the area (near present day Paragould, Arkansas) sometime around 1820. The low lying areas around the ridge were much swampier than they are in the present time and the ridge provided a natural and more healthful place for settlers to establish homes. The ridge became a natural north-south communications link since travel along the ridge was much easier than the through the swampy lowlands.
http://rams.nesd.k12.ar.us/greene/newpage1.htm Crowley's Ridge