In 2018, the Utah State Legislature unanimously approved S.B. 43, designating Utahraptor (Utahraptor ostrommaysi) as the official state dinosaur. Governor Gary R. Herbert signed the bill into law on March 16, 2018 (Utah Code).

Ten-year-old Kenyon Roberts convinced Senator Curtis Bramble (R-Provo) to sponsor bill SB43. Kenyon first proposed the Utahraptor to replace Allosaurus as the Utah State Fossil. However, Allosaurus also has significance in Utah. Kenyon argued in House and Senate hearings that it should be honored in part because it has been found only in Utah, has the state’s name, and is the largest of all raptors. “It’s been millions of years in the making, and it’s time,” said Representative Mike McKell (R-Spanish Fork), the House sponsor of the bill.

Utahraptor specimens were initially discovered in the Dalton Wells Quarry in 1975 by Jim Jensen James Kirkland, Robert Gaston, and Donald Burge discovered Utahraptor in the Cedar Mountain Formation in the Gaston Quarry in 1991. In 1993, they named it Utahraptor, meaning “Utah’s predator” or “Utah’s plunderer.”

Utahraptor ostrommaysi is a carnivorous theropod dinosaur. Utahraptor, a large dromaeosaurid dinosaur, existed approximately 135 to 130 million years ago during the Early Cretaceous period. Dromaeosaurids (meaning “running lizards”) were a genus of feathered, carnivorous theropods. Utahraptor is similar to the velociraptor, except it was much larger. Utahraptor was 20-23 feet in length and weighed around 1,100 pounds.

As a carnivore, Utahraptor hunted other animals within the Cedar Mountain Formation ecosystem, including ankylosaurs and iguanodonts. Unlike other dromaeosaurs, which were pursuit predators, evidence from its leg physiology suggests Utahraptor was an ambush predator. The discovery of fossil remains from multiple individuals of varying ages found together indicates that Utahraptor was social and exhibited some level of post-nestling care.

Utahraptor Scientific Classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: †Dromaeosauridae
Clade: †Eudromaeosauria
Subfamily: †Dromaeosaurinae
Genus: †Utahraptor
Type Species: †Utahraptor ostrommaysi

In 2021, the Utah State Legislature passed H.B. 257 creating Utahraptor State Park. The park is located about 15 miles northwest of Moab in Grand County. The Park officially opened on May 23, 2025.