Which geographic regions did the cross timbers once cover?

The geographic region between the "eastern deciduous forests" and the "grasslands of the southern Great Plains" was once covered by Cross Timbers.

Explanation:

The pre-settlement Cross Timbers were spread over an area as big as 28,000 square miles. The region between the "eastern deciduous forests" and the "grasslands of the southern Great Plains" is believed to have been once covered by the Cross Timbers. Clearing of the land for settlement purposes and to fetch economic gains from the forest produce, unregulated cutting of the Cross Timbers happened fro years which resulted in heavy depletion of this ancient forest. Now the Cross Timbers only exist in the shape of a narrow strip of stretching from Central Texas to Southeastern Kansas, covering the Central part of Oklahoma.

Air pollution: “combustion results in gases such as nitrogen oxides, nitrogen dioxide and particulates. the main causes of air pollution include transport, domestic combustion and industrial processes. pollutants from these sources can cause problems in the immediate vicinity and a distance away.”

Answermost of the time it would be ground into fine sediment,and sometimes they are carried away from the original location;