Page 20a: Two Greyscale Photos [2/27/74] View of centerline of grout cap and rock cavity on upstream side of keyway trench at station 3+55. [4/3/74] View of cleanup on bench below conveyor-tower, station 16+50 to 17+50. Page 20b: Two Greyscale Photos [4/4/74] View of contractor placing zone 1 material on bench at bottom of conveyor tower, station 16+50 to 17+50, centerline of dam to 200 feet upstream from centerline of dam. [4/5/74] View of zone 1 material compacted on bench below conveyor tower.