(225 ILCS 720/3.19) (from Ch. 96 1/2, par. 7903.19)
    Sec. 3.19. Natural Barriers. An undisturbed natural barrier shall be provided beginning at the elevation of the lowest coal seam to be mined and extending from the outslope for such distance as the Department determines shall be retained in place as a barrier to slides and erosion.
(Source: P.A. 81-1015.)