Invasive mudsnails are making waves in Casper

The Wyoming Game and Fish Department has announced it will permanently close Jessica’s Pond in the Casper region later this month after invasive New Zealand mudsnails were confirmed at the site in October 2025.

Note: An earlier version of this article featured an image of zebra mussels; we have updated our featured image to show new zealand mudsnails.

According to the department, the pond will be filled in and the area reclaimed to eliminate the risk of the species spreading further. Officials say the decision followed a full assessment and was largely driven by the pond’s proximity to the Dan Speas Fish Hatchery.

“We recognize the importance of this location as a community fishery and popular recreation spot,” Game and Fish Chief of Fisheries Alan Osterland said. “However, the rate of spread from these invasive snails has led us to the decision to permanently close the location and reclaim the site to prevent further spread.”

While mudsnails have been detected in the North Platte River, officials say the hatchery remains free of the invasive species.

The North Platte River – Wyoming Flycasters Memorial Public Access Area, located adjacent to the hatchery, will remain closed due to mudsnail concerns.

Game and Fish says the Casper region continues to offer premier fishing opportunities along the North Platte River. Anglers looking for an accessible alternative to Jessica’s Pond can visit Yesness Pond in Casper, which features ADA-compliant trails and access points.

Officials are reminding anglers to “Clean, Drain and Dry” all equipment when visiting any Wyoming water. Boot scrubbing stations are available at many fishing access points, and seasonal watercraft inspections are required for boats entering the state.

More information about aquatic invasive species and prevention efforts is available on the Game and Fish website.