Fishing in Montana is a $900 million dollar industry, but a portion of that total may be in jeopardy due to a mysterious disease that has killed thousands of fish in one of the state's premiere fishing areas.

Montana Fish Wildlife and Parks spokesman Ron Aasheim is not minimizing the danger, especially with Labor Day weekend approaching.

"Fishing in Montana is a $900 million industry," Aasheim said. "And, that doesn't include license and permit sales. $900 million from visitors to our state and resident anglers. The Yellowstone stays open year-round, and yes, there is a chance that the closure could remain in effect, or portions of the river could be reopened to say, just rafting or floating. I's interesting that the biologists, the technical experts are convinced, and its been shown that the stress of just people floating over fish in these warmer waters moves them, and that might be an additional stress that results in whether they make it or not."

The unprecedented move of closing over 180 miles of the Yellowstone River began on August 12.

"On August 12th we heard about some dead fish and began testing," he said. "It's a parasite called PKX, and it attacks the kidneys in this case of mountain whitefish and it's very lethal. We're talking tens of thousands of whitefish. It's dramatic. The good news is, not a lot of trout have been affected yet. There are some stressors  like low water levels and high water temperatures, but for now, it's a bugger."

Aasheim said despite the closure of the river, the public and surrounding communities are responding with patience.

"People have been great," he continued. "The Livingston Enterprise did a survey and over 90 percent of the people think the commission made the right decision, but the question is now, how do we move forward? We continue to do testing, and the commission is going to meet again Thursday to decide if there is an opportunity to open parts of the river, and if so, to what types of activity. We're trying to get things sorted out, but we're learning as we go."

Aasheim said testing is being done on the tributaries of the Yellowstone, and there is some optimism.

"We'll have the testing back on those tributaries tomorrow afternoon," he said. "We've done some testing as far down as Laurel. There is some infection down there, but once you get below Big Timber, it's a lot less obvious."

There is a link on the Montana Fish Wildlife and Parks website with a daily update on progress of the investigation into the river's closure.

Meanwhile, outfitters, fishing shops, hotels, motels and communities that depend a great deal on fishing in eastern Montana watch and wait.