MAMMOTH HOT SPRINGS, Wyo. — Yellowstone National Park (YNP) will open its boating and fishing season on Saturday, May 25, with a closing date of Oct. 31.

With the opening, the park is emphasizing the vital role visitors play in preventing the spread of aquatic invasive species (AIS).

Boaters and anglers must clean, drain and dry all boats and equipment prior to arriving in the park.

Yellowstone will implement new measures, including a 30-day mandatory dry time for boats, to help stop the spread of aquatic invasive species (AIS) into park waters, starting on May 25. The 30-day dry time will be required for sailboats and certain complex motorized boats (inboard, inboard/outboard and inboard jet) prior to launching into park waters. There will also be the prohibition of watercraft previously fouled by mussels regardless of dry time.

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. Felt-soled footwear is banned because it can carry microscopic disease organisms even after cleaning.

According to the park, Dreissenid Mussels, including Zebra and Quagga Mussels, are among the world’s most harmful invasive species, with large and widespread ecological and economic effects. If Zebra or Quagga mussels are found in Yellowstone, park waters could close to all watercraft to prevent the spread to other waterways. AIS can quickly and drastically transform habitats and food webs, causing permanent declines in sport fish and food resources for native wildlife.

YNP says that assistance from visiting anglers is a critical part of the conservation effort to reverse the decline of native fish populations in Yellowstone, including cutthroat trout. Anglers can remove nonnative fish, but all native fish must be released unharmed, including cutthroat trout, mountain whitefish and Arctic grayling.

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

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