Watercraft Inspections Resume in Northwest Montana

In an effort to prevent the spread of aquatic invasive species, boaters entering the Flathead Basin are required to undergo inspections prior to launching

By Tristan Scott
A boat is cleaned at an FWP watercraft inspection station in Ravalli. Beacon File Photo

With thearrival of warmer weather and the start of a popular fishing derby on Flathead Lake, officials with Montana Fish, Wildlife are Parks (FWP) have begun offering early-season watercraft inspections in Kalispell, with additional facilities slated to open in Northwest Montana in the coming weeks.

“Inspection stations are the first line of defense to stop the spread of aquatic invasive species,” according to a news release from FWP, which is offering watercraft inspection at its Kalispell office.

The increased visibility of watercraft inspection stations is becoming a familiar indicator of spring in Montana following the November 2016 discovery of destructive mussel larvae in Tiber and Canyon Ferry reservoirs east of the Continental Divide, marking the first time the invasive species have been detected in state waters and pulling a dire scenario into grim focus.

So far, the traces of contamination are restricted to the Missouri River Basin, but the likelihood of mussels hitchhiking on the hulls of boats or in bilge water or hidden away in irrigation equipment has prompted state and tribal agencies to launch a multi-pronged plan that includes bolstering perimeter defense to intercept mussel-fouled boats.

A total of 35 mussel-fouled vessels were intercepted in 2020, according to FWP officials.

For now, motorized and non-motorized boaters should visit the FWP Region 1 office at 490 North Meridian near the Flathead County Fairgrounds for an inspection, with hours extending from 8 a.m. to 5 p.m. Monday through Friday. The inspection station will increase its availability starting April 5, with operational hours remaining the same during weekdays but running from 9 a.m. to 5 p.m. on weekends and holidays. Additional inspection stations will begin opening across the state in the coming weeks and months, including a station in Ravalli on March 12.

In Northwest Montana, the Spring Mack Days fishing derby begins March 19, and all boats participating in the event must be inspected before launching at any site on Flathead Lake. Although the purpose of the fishing derby is to encourage the over-harvesting of invasive lake trout in Flathead Lake by offering cash incentives, it also increases early-season boating pressure on the largest freshwater lake west of the Mississippi, as well as the chances for a mussel-fouled boat to slip through unchecked.

“Watercraft inspections are mandatory for anyone entering Montana from out-of-state,” according to FWP. For boaters who do not encounter a Montana watercraft inspection station while traveling, inspections conducted in Idaho and Wyoming fulfill Montana’s inspection-before-launch requirements. However, the boaters must carry a proof of inspection receipt and, when applicable, an intact seal.

Boaters must stop at all open inspection stations they encounter in Montana, where watercraft may be re-inspected, and an inspection is required for any boaters traveling west over the Continental Divide into the Columbia River Basin — the only major watershed in the West still believed to be free of quagga and zebra mussels.

Nonresidents boaters launching watercraft in Montana must purchase a Vessel AIS Prevention Pass, which costs $30 and applies to all motorized watercraft that is registered in another state or country. The fee for nonmotorized watercraft is $10 and applies to all non-motorized watercraft that nonresidents bring into Montana. Nonresidents can purchase the Vessel AIS Prevention Pass online at or at any FWP office. Proof of purchase is an electronic or paper receipt. Nonresidents passing through Montana and not launching a watercraft are not required to purchase the pass.

AIS are introduced accidentally or intentionally outside of their native range. AIS populations, such as zebra or quagga mussels, can reproduce quickly and spread rapidly because there are no natural predators or competitors to keep them in check. AIS can displace native species, clog waterways, impact irrigation and power systems, degrade ecosystems, threaten recreational fishing opportunities, and can cause wildlife and public health problems.

For a map of the Flathead Basin, visit

For more information on Montana’s campaign to prevent aquatic invasive species, visit

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