Therefore ere the Third Age was ended the Elves perceived that the Ring of Sapphire was with Elrond, in the fair valley of Rivendell, upon whose house the stars of heaven most brightly shone; whereas the Ring of Adamant was in the Land of Lórien where dwelt the Lady Galadriel. A queen she was of the woodland Elves, the wife of Celeborn of Doriath, yet she herself was of the Noldor and remembered the Day before days in Valinor, and she was the mightiest and fairest of all the Elves that remained in Middle-earth. But the Red Ring remained hidden until the end, and none save Elrond and Galadriel and Círdan knew to whom it had been committed.
Of the Rings of Power and the Third Age, The Silmarillion