MAMMOTH HOT SPRINGS, Wyo. — Yellowstone National Park (YNP) 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 Saturday, May 25.
May 25 is the first day of Yellowstone’s boating and fishing season. The season wraps up on Oct. 31 annually.
According to YNP, the park faces an increased risk of invasion by highly invasive zebra and quagga mussels following recent detections (2022 Pactola Reservoir in South Dakota; and 2023 Snake River in Twin Falls, Idaho) in waterways within a day’s drive of the park.
“Mussels have caused irreversible ecological damage and extensive impacts to infrastructure and recreation in waterways throughout the Midwestern and Eastern United States, as well as in the lower Colorado River Basin,” YNP said in the announcement. “In both 2022 and 2023, Yellowstone’s AIS inspectors intercepted and denied launch to mussel-fouled watercraft, highlighting the urgency and severity of the threat.”
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.
“Manual decontamination with the use of hot water is not always 100% effective in removing all mussels,” YNP said on Facebook. “A 30-day dry time will mitigate the risk.”
These new restrictions will build on existing protections, including the 2019 prohibition on watercraft equipped with sealed internal ballast tanks, as well as the 2022 prohibition of watercraft with evidence of live or dead mussels.
Prevention of AIS introduction protects Yellowstone’s cutthroat trout population and the ecological integrity of park waters. There are currently no eradication methods to remove AIS infestation, according to YNP.
The park recently concluded a 30-day public comment period, and the majority of comments received were in favor of the newly implemented restrictions.
Boaters and anglers are reminded to clean, drain and dry all boats, trailers and equipment prior to arriving in the park. Felt-soled footwear is banned because they can carry microscopic disease organisms even after cleaning. Additionally, clean all plants, animals, mud, sand and other debris from the boat, anchor, boots and equipment. Use high-pressure, hot (120-140 F) water if possible. Drain all water from the boat, including the motor, bilge, livewell and other compartments. Leave drain plugs out during transport. Dry all compartments and equipment in the sun for five days.
More information about the new AIS regulations can be seen here.
