Arizona has the distinction of accomplishing something that several other states failed to at the start of the 20th century.

The state killed off its prairie dogs.

“In the early 1900s, they started a poison campaign to get rid of prairie dogs,” says Holly Hicks, a small mammals biologist for the Arizona Game and Fish Department. “They were seen as competition for a lot of livestock.

"State and federal agencies combined on the effort, and Arizona was the only state successful in eradicating black-tails, and so most of them were gone by the 1930s," Hicks says. "I think the last prairie dog was seen in 1961 here in Arizona.”

Several entities are working to bring the black-tailed prairie dog back to Southern Arizona. In 2008, the state reintroduced 74 black-tailed prairie dogs to Las Cienegas National Conservation Area southeast of Tucson.

Historically, Arizona had two types of prairie dogs, Gunnison’s in the north and the black-tailed in the south. The black-tailed, one of five types that live in the United States, has the widest range. It was found in western North America from Canada to Mexico.

“We mark them so we can tell apart individuals from each other,” says Sarah Hale, a graduate assistant with the School of Natural Resources and the Environment at the University of Arizona. For her research Hale is trapping black-tails at Las Cienegas and then uniquely marking each one with black paint.

“That way we can get accurate counts of the population without recounting the same individual and missing another," Hale says. "And we can also tell who’s interacting with whom, if it’s male or female, juvenile or adult and other details.”

That is information researchers hope will quantify the importance of reestablishing prairie dogs in their traditional ranges.