Altoona, Pa. . 1 map on 23 sheets : col. ; on sheets 64 x 54 cm. Oriented with north to the upper right, with some sheets on the horizontal; Set follows standard Sanborn color keying; Title from upper right corner of sheet 2; Maps Library copy lacks sheet 1 and all sheets are encapsulated. Scale approximately 1:600. 50 ft. to an in.