Geographic Variety of the State

Over 600 million years (Paleozoic era)  ago Arkansas was covered with water. As the water drained away the Ouachita mountains appeared and then the Ozark mountains.  About 230 million years (end of the Mesozoic era) the Coastal Plaines and the Delta stayed permanently above water. Nature continued to shape the area but no glaciers ever reached Arkansas. The essential features of the state were present about one million years ago.  Climate and man have continued to reshape the area.

     Michael Dougan  Arkansas Odyssey


Check the following links for information about the geology/geography of Arkansas  You do not have to read all the links, I just want you to gain an understanding of how varied the terrain of Arkansas is and the fact that in Arkansas dinosaurs roamed and ancient peoples lived here and left a mark.

Be sure to note the differences and be aware of time periods and changes which occurred (it is not necessary to learn dates of   changes so much as to know  the changes which occurred in the correct time frame)of Arkansas 

 Geologic History This site is a simple discussion of the geologic time scale.

Rock hounding


   Fossil newspaper article

The King Mastodon Excavation

Ouachita Mountains   Novaculite      

        The Caddo Map Tool, Environment - Photo of Novaculite Quarry


Six Natural Regions of Arkansas

Although Arkansas is most easily divided into two distinct geographical regions, the northwestern uplands and the southeastern lowlands, this description does not accurately portray the state's geographical complexity. There are actually six geographic sub-regions, three in both the uplands and the lowlands. The northwestern uplands are made up of three distinctive sub-regions: The Ozark Mountains, the Arkansas River Valley, and the Ouachita Mountains. The southeastern lowlands are comprised of the Gulf Coastal Plain, the Mississippi Alluvial Plain (the Delta), and Crowley's Ridge.

bullet The Ozark region of Arkansas is located in the extreme northern and western portions of the state. This area is marked by flat-topped mountains, or plateaus, which have been eroded over millions of years.
bullet The Arkansas River Valley is the area carved by the river long ago. This 40-mile wide trough divides the Ozark and Ouachita Mountains. Most of Arkansas's larger cities can be found in the river valley-Fort Smith, Little Rock, and several others.
bullet The Ouachita Mountains lie south of the river valley. These mountains run east to west and are largely covered in pine trees. The soil here is even worse than that of the Ozarks. There are many unusual features here including Hot Springs and the diamond crater at Murfreesboro.
bullet The southern part of Arkansas is part of the Gulf Coastal Plain. This area was once covered by the Gulf of Mexico and emerged from the sea 50 million to 100 million years ago. Today there is much agriculture and timber in this area, as well as oil and natural gas deposits.
bullet The Delta, or Mississippi Alluvial Plain, covers the eastern portion of Arkansas. Here the Mississippi and numerous other rivers have deposited rich soils over millions of years. This area has swamps, prairies, and rich farmland where the soil is very deep. Today this region is the primary agricultural part of Arkansas.
bullet Crowley's Ridge divides the eastern part of Arkansas. The ridge is composed of loess (windblown soil) and runs for 150 miles north from Helena. It varies in height from 250 to 500 feet above sea level. Crowley's ridge was originally an island between the Mississippi and Ohio rivers. When these rivers shifted their courses millions of years ago, Crowley's ridge was left behind as a long, low hilly formation. Most of the major cities of the Arkansas Delta can be found on or near Crowley's Ridge.

Because of the diversity of the Arkansas landscape, the state has long been fragmented, or divided. For instance, the hill people of the Ozarks and Ouachitas are much different than the farmers of the Delta. The state is hard to define, and in large part this helps explain the image problems Arkansas has long suffered. By studying the landscape and geography of Arkansas, we can make much progress toward an understanding of the state, its people, and its rich history.