More than 80 second grade students from Cortez Elementary, a math and science magnet school in Pomona, Calif., took a field trip to Prado Dam May 16. The tour included a nearly two-mile trek through the flood control basin up to the dam's 627-foot control tower. William Kramer, a dam operator with the district assigned to Prado Dam, shows students the gate controls during a portion of the field trip.