On a Monday afternoon last October, scientists with Montana Fish, Wildlife and Parks received jarring news.

Researchers from the federal Bureau of Reclamation’s Detection Laboratory for Exotic Species, taking samples in Tiber Reservoir, had pulled up a piece of shell. Testing at the Denver lab suggested it was from a quagga mussel.

Most quaggas measure an inch or less. Their larvae, called “veligers,” are microscopic. But with few North American predators, the Eurasian mollusks can form immense masses.

Since ships brought them to the continent in the 1980s, quagga mussels and their relatives, zebra mussels, have hitchhiked across America on the hulls and in the ballast tanks of recreational boats. When they infest a new water body, they can filter out the plankton that support food chains and block water and power plants’ intakes. The government places their cost in the billions.

By now, only one major U.S. watershed, the Columbia River Basin, has escaped infestation. That could change if the mussels cross the Continental Divide.

“If invasive mussel populations become established in the Pacific Northwest, it is estimated to cost our region $500 million every year just to manage the effects of an infestation,” a bipartisan group of area lawmakers warned U.S. Secretary of the Interior Ryan Zinke in June 2017.

The Bureau’s 2016 sample, if confirmed as quagga, would have signaled that this threat had reached the Columbia’s doorstep.

“Not so good,” wrote Gail Johnson, FWP’s lead lab technician, when she and her colleague, lab manager Stacy Schmidt, got the news on Oct. 17, 2016.

One year after that finding, the Daily Inter Lake is examining the Treasure State’s response to an ecological emergency. This article, the first of a two-part series, details the start of that effort, drawing on state emails obtained through the Freedom of Information Act and interviews with those present.

Long before the federal scientists found that shell, the prospect of a mussel invasion had drawn deep concern from Montana policy-makers. Their plans were put to the test in the weeks that followed, as officials raced to confirm the threat, assess its scope, and inform the public.

The state’s main aquatic invasive species staff were in Jackson, Wyoming, when the federal report came.

“We immediately started making phone calls and making arrangements,” remembers Eileen Ryce, fisheries administrator for Fish, Wildlife and Parks, in an interview.

The 2009 Montana Aquatic Invasive Species Act gave the governor authority to declare an invasive species emergency and release funds to contain the threat. But first, the biologists who monitor the state’s waterways had to confirm that quagga mussels had, in fact, arrived.

“We have protocols in place on what to do,” Ryce explained, describing procedures rehearsed through table-top exercises. “Our first reaction was to go through the process in order to confirm the suspect.”

“We’ve been looking for them for a very long time,” she said. Tiber Reservoir, where the first suspect was found, had been regularly sampled since 2005. As the federal government worked to confirm its initial finding, Johnson began testing recent samples of Tiber water for those microscopic mussel larvae called “veligers.”

Three of the samples, all taken the previous July, turned up suspects.

“Stacy, this is not fun,” Johnson wrote to Schmidt.

Worse news came on Oct. 19, when the initial shell tested positive for quagga mussel DNA.

The problem remained confidential, but knowledge within Fish, Wildlife and Parks was spreading. Region Four supervisor Gary Bertellotti sought quick action.

“Fisherman [sic] that I talked to move from Tiber to [Lake Frances] to Holter over a two-day period at times. Several say they have already done this,” he explained in an Oct. 25 email to the agency’s then-director, Jeff Hagener, and others.

“All the dollars spent to educate and keep from getting them in our state and not to do an all-out effort to keep this contained seems counter to our efforts if we do not put an effort that is equivalent with the preventative and education effort we have put in.”

In a follow-up message, he likened their situation to recent Yellowstone River pipeline breaks and parasite outbreaks, “with one exception, this has the potentioal [sic] of affecting a larger area, higher economic impact for a longer/forever time frame.”

But other agency staff urged patience.

“We are a long ways from confirming it is a positive,” wrote Ryce, explaining that testing up to that point had yielded very low densities, and that low water temperatures that time of year would keep the larvae from reproducing.

“We typically try to not release things haphazardly without being prepared,” Ryce told the Inter Lake.

That was the right approach, said aquatic invasive species expert Rob McMahon.

“You do not want to say a lake is infested based on a shell fragment,” McMahon, professor emeritus at the University of Texas-Arlington, said in a phone interview.

“Here in Texas, there are lakes where DNA has been found, where the odd mussel has been found, and they aren’t really infested.”

The mussels’ biology, he continued, makes it difficult for a single organism to establish a population.

“You don’t want to tell the public that you have an infested lake unless you know it’s really infested.”

Schmidt found scant evidence of a large population on the Tiber’s shoreline, even on the hard surfaces where the mussels often attach. “That was some primo habitat and we found nothing,” she told Ryce the night of Oct. 25.

But the challenge of fighting a nickel-sized animal in America’s fourth-largest state was growing clear. “Remember,” she said, “after finding 3.5 alleged veligers in a water body that has ... 21,300 water surface acres and 181 miles of shoreline, the chances of finding adults is slim.”

Their evidence, however, was strong enough to move the response forward.

On Friday, Oct. 28, after Fish, Wildlife, and Parks mussel experts met with director Hagener, they drafted a press release with the news that three samples taken from Tiber and one from Canyon Ferry over the summer were suspected for quagga and zebra mussel larvae.

“We will likely be going public [Wednesday] afternoon,” Ryce told Schmidt and aquatic invasive species coordinator Tom Boos on Oct. 31.

But Gov. Steve Bullock’s office had other plans.

On Wednesday, Nov. 2, Ryce and Hagener went to meet with the governor. The following day, Hagener sent a message to his agency’s Communication and Education Administrator Ron Aasheim and Information Bureau Chief Greg Lemon: “Instruction from gov office was to hold press release until next week.”

“I remember the release being ready to go on Monday the 7th,” Lemon told the Daily Inter Lake. But after discussions with the governor, it was decided to wait until Wednesday, Nov. 9.

Election Day was Nov. 8, and Gov. Bullock was engaged in a tightly fought re-election campaign against Bozeman businessman Greg Gianforte.

The way Lemon remembers it, he was concerned that “the story wouldn’t get the attention it deserved” if it came out prior to the hoopla surrounding Tuesday’s election, which included not just the gubernatorial race, but Ryan Zinke’s re-election campaign for Congress and the once-in-a-lifetime presidential campaign featuring upstart businessman Donald Trump.

“The last thing we wanted to do,” he said, “was to have any kind of appearance that we were trying to bury this.”

Whatever the delay’s cause, Ryce maintained that it didn’t slow down the state’s response. McMahon also doubts that it had any impact. “In one week, you can’t get inspection stations in place, you can’t get cleaning stations, and it wouldn’t change the situation,” he said, adding that “once they’re in a lake, there’s not much you can do to get them out.”

That reality was captured in the press release finally sent out Nov. 9, which confirmed positive larvae tests in Tiber Reservoir, and stressed the need to keep them there.

“The results from Tiber Reservoir exist at very low densities, which improves our chances for containment,” it quoted Ryce as saying.

“In terms of our response to identify the suspect was positive, I think we handled things well,” she reflected in her Daily Inter Lake interview.

Within days of the press release, dog teams arrived from Alberta to search for additional mussels along Tiber’s shoreline. According to the state’s mussel response website, Tiber remains the only Montana waterbody where veligers have been confirmed (the results from Canyon Ferry remain “suspect”).

But those early tests prompted Gov. Bullock to declare a natural resource emergency on Nov. 30, clearing the way for state resources to address the problem.

Tomorrow, the Daily Inter Lake will examine that response.

Reporter Patrick Reilly can be reached at preilly@dailyinterlake.com, or at 758-4407. Sam Wilson contributed reporting to this article.