There, in the Arkoma basin, the Arkansas River valley follows the general east-west trend of the fold axes. Both folding and faulting decrease northward as this section of the Ouachitas gradually merges with the homoclinal south flank of the Boston Mountains. Relief also diminishes, but some mountains still exceed 700 m in elevation. Topography is similar to that of the folded Appalachians with homoclinal and generally linear ridges, but curved around plunging noses. Although it is difficult to determine dip on homoclinal ridges in the anticlinorium because of steepness of dip, scarp and dip slopes are more easily determined in the gentler folds.
Trellis drainage is prevalent with subsequent strike valleys and crosscutting water gaps.
Many ridges are breached at faults, manifested by offsets of the ridge line.