More than 1.3 million people visited the Detroit Zoo last year, a total the zoo in suburban Royal Oak hadn't reached since 1997.
It also marked the eighth consecutive year in which the Detroit Zoo's annual attendance exceeded 1 million.
The 2013 attendance figure was 1,304,114. That's up from 1,272,574 in 2012.
Officials say the zoo's Wild Lights holiday light display contributed to the strong attendance figure.
Wild Lights continues through Sunday.