Anglers Beware: Yellowstone National Park is Bordering an Invasive Species Problem

by Jon D. B.

Certain invasive species could completely close Yellowstone National Park waters to all watercraft to prevent spread, the park says.

“Kill and report any smallmouth bass if caught within park waters,” Yellowstone National Park (YELL) told visiting anglers earlier this year. It’s a request that remains very much in place. Back in February, an invasive predatory smallmouth bass was caught at the confluence of Gardner and Yellowstone rivers just north of the park’s boundary in Montana. Although no evidence of the species has been found in park waters since, officials aren’t taking any chances.

“Since anglers are highly effective at suppressing invasive fish in waters where they coexist with native species like cutthroat trout, the regulations now require them to kill and report any smallmouth bass if caught within park waters,” the park continues in their May 23 media release, a key update ahead of Yellowstone National Park’s boating and fishing season opening for 2022 on Saturday, May 28.

But smallmouth bass may be the least of their worries. Any and all AIS pose a grave threat to ecosystems. When it comes to Yellowstone National Park and the Greater Yellowstone Ecosystem, however, there’s a handful of species that have park officials on high alert. They are:

  • Dreissenid Mussels
  • Zebra Mussels
  • Quagga Mussels

Currently, Yellowstone lists these three species as “potential future threats.” Dreissenid Mussels, including Zebra and Quagga Mussels, “are among the world’s most harmful invasive species,” they continues. Each holds the potential for large and widespread ecological and economic effects.

In short: Yellowstone is entering full AIS-prevention mode ahead of 2022’s fishing and boating season.

If Zebra or Quagga mussels are found in Yellowstone, park waters may close to all watercraft to prevent the spread to other waterways

Man holding a handful of Zebra mussels near Kingston, Canada, which have invaded Lake Ontario. Zebra mussels from the Caspian Sea, introduced to North America by accident, are becoming a veritable plague releasing toxic chemicals into the Great Lakes, Canadian biologists say. The mussels hitch-hiked to Canada on the ballasts of cargo ships arriving on the continent in 1986. And in the past two decades the thumbnail-sized creatures have spread and are found in more than a third of the Great Lakes. (Photo credit: Kilian FICHOU/AFP via Getty Images)

“If Zebra or Quagga mussels are found in Yellowstone,” in fact, “park waters may close to all watercraft to prevent the spread to other waterways,” YELL adds.

The park continues to develop an AIS Management Plan and Rapid Response Framework alongside local states. In the meantime, boaters and anglers can now help prevent the spread of aquatic invasive species (AIS) and protect park waters as angling and boating season begins.

Yellowstone National Park Boating & Fishing Season Begins Saturday, May 28 – Closes Oct. 31

To help manage AIS, Yellowstone National Park is enforcing their clean, drain and dry program:

“Boaters and anglers must clean, drain and dry all boats and equipment prior to arriving in the park to minimize the risk of introducing AIS into Yellowstone’s waters. Watercraft equipped with sealed internal ballast tanks are banned from all park waters as inspections cannot always detect aquatic invaders in these types of boats. In addition, felt-soled footwear is banned because they can carry microscopic disease organisms even after cleaning,” the park states.

Clean – Drain – Dry

Yellowstone boaters and anglers, ensure you do not bring AIS to the park by doing the following:

  • Clean all plants, animals, mud, sand and other debris from your boat, anchor, boots and equipment
    • Use high-pressure, hot (120-140F) water if possible.
  • Drain all water from your boat, including the motor, bilge, livewell and other compartments before you arrive
    • Leave drain plugs out during transport
    • Do not move water or organisms from one water body into another
  • Dry all compartments and equipment in the sun for five days

Following clean, drain and dry requirements will protect the park’s and nation’s waterways. These steps are critical, the park says, and will be strictly enforced until the season closes on Oct. 31.

Yellowstone Requiring AIS Inspection Prior to Launching in Park Waters

As a result, all watercraft and angler float tubes must have a Yellowstone National Park permit and AIS inspection prior to launching in park waters.

Permits and inspections are available for purchase 8 a.m. to 4:30 p.m. seven days per week during the summer season at the following locations:

Motorized and non-motorized watercraft (including angler float tubes)

  • Bridge Bay Ranger Station
  • Grant Village Backcountry Office
  • Lewis Lake Ranger Station

Angler float tubes only

  • West Yellowstone Visitor Information Center
  • Bechler Ranger Station
  • Mammoth Hot Springs Backcountry Office
  • Northeast Entrance

For anglers, Yellowstone National Park fishing permits are available for purchase in park stores. Vendors in surrounding communities also carry them, or you can go online via