Held Saturdays, Sundays & Halloween through September 21 – October 31 from 10 a.m. – 6 p.m., the zoo will be decked out with Halloween fun complete with trick-or-treat stations, pumpkin painting, dance parties, costume contests and plenty of games. Families can even enjoy a ride on the Zoo Boo! Express. Little ghouls and goblins are encouraged to wear their best costume* for a chance to be in a costume contest. Zoo Boo! is included with zoo standard admission and FREE for zoo Annual Pass holders.