The contest is put on by USA Today’s 10Best program.
Cheyenne Mountain Zoo took 6th place in 2017.
Both zoos need the public’s help in snagging that 1st place spot, but only one can win that top spot. Fans can cast their votes once a day, every day through 10 a.m. on April 30.
As of Sunday afternoon, CMZ sat in 4th place out of 20, following Saint Louis Zoo, Omaha’s Henry Doorly Zoo and Aquarium and the Arizona-Sonora Desert Muesum – Tucson.