Crowley's Ridge is a unique geologic formation located in which part of Arkansas?

Crowley's Ridge is a significant and distinctive geological formation found in Eastern Arkansas. It is characterized by a series of low, rolling hills, and it runs approximately 200 miles from the Missouri border down to the Mississippi River. This ridge stands out in the region due to its elevated terrain, contrasting with the surrounding flatlands of the Mississippi Alluvial Plain.

The prominence of Crowley's Ridge is due primarily to its composition of ancient river sediments and its unique ecological features, which include various plant and animal species not commonly found in the surrounding areas. Its location in Eastern Arkansas is also vital for understanding the state's geology, ecology, and even its cultural history, as it has been home to various communities and is integral to the local landscape.

The other regions mentioned do not have the same geographic and geological characteristics associated with Crowley's Ridge. Hence, the correct identification of this formation in Eastern Arkansas provides a clear understanding of its significance in the state's natural and cultural heritage.