Detroit Zoo (Michigan): Covers 125 acres and features naturalistic habitats for its 2,400 animals representing 235 species.
Denver Zoo (Colorado): Encompassing 80 acres, it houses over 4,000 animals from 750 species, with a focus on innovative habitats and conservation efforts.
Houston Zoo (Texas): Spans 55 acres and is home to over 6,000 animals from 900 species, attracting more than 2 million visitors annually.
Brookfield Zoo (Illinois): Located in the Chicago suburbs, it covers 216 acres and is home to around 450 species of animals.
Saint Louis Zoo (Missouri): Free to the public and covering 90 acres, it features over 17,000 animals from about 600 species.
Smithsonian National Zoological Park (Washington, D.C.): Part of the Smithsonian Institution, it spans 163 acres and houses around 2,700 animals representing 390 species.