Senate district twenty-one is composed of Bernalillo county precincts 339, 360 through 362, 390, 398, 410, 418 through 420, 422 through 427, 429, 430, 447, 448, 456 through 460, 467 through 470, 479, 485 through 487, 489, 501, 510, 520, 541, 560, 568, 584 through 590, 592 through 594, 598, 601, 602, 608, 664, 665, 667, 669, 673, 674 and 682 through 685.