Colorado Democrats ask Trump administration to act on invasive zebra mussels

Several Colorado Democrats are using the recent detections of zebra mussels in the Colorado River to push for implementation of key provisions in the Expanding Public Lands Outdoor Recreation Experiences Act.

The EXPLORE Act, as it’s more commonly known, passed in December 2024 and contained multiple bills around improving public land access and conservation, including the aptly named “Stop the Spread of Invasive Mussels Act.” 

The law gave new authorities to the U.S. Department of the Interior and U.S. Department of Agriculture to respond to and monitor aquatic invasive species. 

This includes provisions to strengthen partnerships among the Interior Department’s Bureau of Reclamation and state and local governments to fund and implement preventative programs such as watercraft inspection and decontamination stations. It also proposes that any federal agency involved in the Aquatic Nuisance Species Task Force will have the authority to limit the movement of invasive species into and out of U.S. waters and seek to improve data sharing between agencies. 

On Friday, Colorado Democratic Rep. Joe Neguse, who championed the EXPLORE Act, wrote a letter with Sens. Michael Bennet and John Hickenlooper, asking the Interior and Agriculture secretaries for an update on the law’s implementation, calling specific attention to the section on mussels. 

“We understand the many pressures on your agencies but request that you prioritize the implementation of these provisions in light of the threat facing our waterways and rivers in the West,” they wrote. 

The letter requests answers to several specific questions by Aug. 29, asking when the new authorities will be fully implemented, what the federal departments are doing to combat the spread of invasive mussels in the U.S., and whether they’ve offered assistance to stop the spread in Colorado. 

The letter refers to recent discoveries of zebra mussels made by Colorado Parks and Wildlife in Western Colorado. First detected in the state in 2021, discoveries of adult and veliger zebra mussels have ramped up this summer with positive samples in the Colorado River, Highline Lake, Mack Mesa Lake, and a private lake in Eagle County, which authorities now believe was the primary source of the state’s detections. 

“More than 40 million people across seven states rely on the Colorado River Basin, and the spread of these invasive species into this critical body of water could have devastating impacts for many communities across the West,” wrote the lawmakers. 

Zebra mussels — and their microscopic, free-floating larvae called veligers — are notorious for their prolific reproduction and destruction of ecosystems and infrastructure.