There are fewer eastern species here. Pockets of deep clay soils support bluestem prairies. Gray squirrels occur only in hardwood bottoms. The Oak Woodlands contain the best developed oak-hickory forest in Texas. Gray squirrels are abundant.
Prairies are more common than in the other subregions.
The peat bogs mentioned above are found here. The Eastern Cross Timbers is best described as a mix of the Western Cross Timbers and the Oak Woodlands. Itsphase of development falls between those of the Oak Woodlands and Western Cross Timbers.