A polymer stall divider for a barn will permit lateral flexing when a cow presses against the stall divider while the stall divider asserts a lateral force against the cow to urge the cow to move into a proper position between adjacent stall dividers without causing injury to the cow. The polymer stall divider can be formed of a polymer material clad onto the outer surface of a steel structural member and then bent into shape to form the desired configuration. The divider can be formed in sections with adjacent sections being connected by an internal connector formed of selected materials to provide the desired flexibility and durability characteristics. A mounting bracket formed of a pair of opposing clam shells can be utilized to secure the stall divider to the frame of the barn, thus providing an easily installed divider structure.