For a minute, I thought I had stepped into that scene from Lawrence of Arabia where T.E. Lawrence, approaching the Suez Canal, sees a ship sailing across the sand. Only I saw it in a farm field with cattle. I had parked on a levee at the north end of Twitchell Island, in the middle of the great Sacramento-San Joaquin river Delta, east of San Francisco. In front of me was prime farmland – a busy mosaic of pasture land and row crops as far as the eye could see – and just beyond a slight rise in the distance I saw a big cargo tanker plowing its way slowly across the farm field. Of course, it was plowing the middle of the San Joaquin River instead.