  H9255WD/71-- OPR-467-RH-71,72; ITEM NO. 44; 1:20,000-SCALE SURVEY; RAYDIST CONTROL (HYPERBOLIC, R/R) AND VISUAL. LEADLINE, 2 X 2 X 2-FOOT CONCRETE BLOCK, HUNG AT 19 FEET (ESTIMATED). CLEARED BY18 FEET; LEAST DEPTH BY LEAD LINE OF 19 FEET; DEPTHS IN ARE