| State | Official Dinosaur (year it became official) |
|---|---|
| Colorado | Stegosaurus stenops (1991) |
| Connecticut | Eubrontes giganteus (an ichnogenus) (1991) |
| District of Columbia | Capitalsaurus (June 10, 1998) |
| Maryland | Astrodon johnstoni (1998) |
| Massachusetts | Theropod footprints (1980) |
| Montana | Maiasaura peeblesorum (1985) |
| New Jersey | Hadrosaurus foulkii (1991) |
| New Mexico | Coelophysis bauri (1981) |
| Oklahoma | Saurophaganax maximus (2000) |
| South Dakota | Triceratops prorsus |
| Texas | Pleurocoelus (1997) |
| Utah | Allosaurus fragilis (1988) |
| Wyoming | Triceratops horridus (1994) |