Harvest Volumes per acre shall be based on site index and the ability of the site to yield timber measured in thousands of board feet (MBF) per acre (Scribner rule) or cords per acre with harvest intervals at thirty-five (35), fifty-five (55) and eighty (80) years for Grade 1 and Grade 2 soils, and at forty-five (45) and eighty (80) years for Grade 3 soil.
W. Va. Code R. § 110-1H-9