1st Western Diamondback Rattlesnake officially documented in Denton County

DENTON COUNTY, Texas - The University of Texas at Arlington’s Amphibian and Reptile Diversity Research Center (ARDRC) recently documented Denton County’s first Western Diamondback rattlesnake in the county's extensive herpetology research collection. 

Western Diamondback Rattlesnake in Denton County

What we know:

According to the university, Denton County citizen scientists discovered a rattlesnake in an Argyle garage on Nov. 6, 2025, marking the first Western Diamondback Rattlesnake in the county. 

Western Diamondbacks typically inhabit desert regions, making their presence in forested DFW counties rare. 

In this instance, experts believe the snake likely was seeking shelter, as many do when temperatures drop. 

Rattlesnake discovery surprises researchers

What they're saying:

There have been small pockets of Western Diamondbacks in similar environments documented over the years, but this is the first documented Western Diamondback in Denton County.

"For decades, even hundreds of years, there have been scientists and herpetologists in Texas collecting specimens for research and making official records of the species occurring, yet there’s never been one officially recorded from Denton County," said Greg Pandelis, collections manager at the ARDRC and coauthor of the latest scientific publication on the distribution of Texas reptiles.

Pandelis believes the snake came from a small undetected population within Denton County rather than migrating from neighboring areas.

"This is especially odd because of how common that snake generally is," Pandelis said. "It’s not something that usually eludes detection. So this specimen is very important and interesting because it will reform our understanding of not just where the species occurs in Texas, but maybe even what its habitat requirements are and what its limits are, as far as where it can occur and where it can’t. Having this individual snake preserved as a research specimen is so important because it will fill a gap in our understanding of this species and will be used in studies being done on Diamondback biology," said Pandlis.

Citizen scientists contribute to UTA research

Local perspective:

For Pandelis, this latest discovery highlights the value of collaboration between the public and the scientific community.

He recommends that the public contact professionals if they encounter a snake in a similar situation. An added benefit is potentially making history, as in this case. If a snake is preserved as a specimen, it provides lasting research value, from genetic and venom analyses to color studies.

"We had some citizen scientists discover something cool, reach out to us and contribute to science by depositing the specimen here," Pandelis said. "Now, we’re helping them publish the first report on this. It’s a great interplay between UTA, the ARDRC and the public that I’d like to see more of in the future."

Inside the ARDRC

Dig deeper:

The snake was added to the county’s herpetology research collection after the citizen scientists then contacted the ARDRC and donated the rattlesnake to be studied in detail by UTA’s experts. The university experts also helped submit documentation for a new discovery in scientific literature. 

The ARDRC is among the top 10 amphibian and reptile collections in the world, with more than 200,000 specimens. 597 of those being Western Diamondback specimens, 403 of which originate from Dallas, Jack, Parker and Tarrant counties.