The Blackfeet Nation announced Monday it would close all its waters to both motorized and non-motorized boats, citing last week’s announcement confirming Montana’s first-ever detection of invasive mussels in the nearby Tiber Reservoir.

The tribe’s announcement comes days after Glacier National Park issued a similar edict, temporarily closing all bodies of water within the park boundaries to watercraft until the extent of the mussels’ spread can be determined by updated water sampling.

The closure applies to all waters within the Blackfeet Reservation. Anglers will still be able to fish from the shore and ice-fish, according to Blackfeet Fish and Wildlife Director Dona Rutherford.

She noted in an interview Monday that the tribe has yet to detect any mussel larvae in the of the bodies of water within the reservation’s borders, but would not lift the boating closure until sometime the following spring, at the earliest.

“The Tiber Dam is about an hour away,” she said. “We’ll probably have to start testing again in the spring.”

Since 2015 the tribe has required all motorized and non-motorized watercraft to be inspected for aquatic invasive species prior to launching in Blackfeet waters. Two watercraft inspection stations operate during the regular boating season on U.S. 2 in Browning and outside of Cut Bank.

Montana Fish, Wildlife and Parks announced last Wednesday that water samples taken in the summer revealed the presence of mussel larvae in Tiber, and indicated possible mussel contamination in the Canyon Ferry Reservoir near Helena.

The state wildlife agency has not issued any closures related to the findings as of Monday, and a spokesman for Waterton Lakes National Park — directly across the Canadian border from Glacier — said the park was monitoring the situation but was keeping its waters open to boats for the time being.

For more information on the Blackfeet Nation’s boating closure, contact Rutherford at 406-338-7207.