As October begins, fishing fades into the background as sportsmen anticipate the start of rifle season. But for those still wanting to wet a line, the cooler weather has meant cooler water and increasing access to rivers that closed due to the summer heat. While some anglers understand the need to close rivers, it appears that legislators don’t. So they may challenge Fish, Wildlife & Parks’ decisions during the 2017 Legislature.

On Friday, FWP reopened most of the Big Hole River, the only stream in the state still under restrictions. However, the lower section from the Notch Bottom Fishing Access Site to the Jefferson River at Twin Bridges remains closed, according to criteria outlined in the Big Hole Watershed Drought Management Plan.

The Big Hole River receives a bit more scrutiny than streams in the rest of the state, because it is home to Montana’s remaining population of arctic grayling. It’s also in a part of the state that is dealing with increasing drought. This summer, the river’s flow in the lower section plummeted from a high of around 3,000 cubic feet per second in the first week of June to 200 cfs by August 1. Because of the low levels, water temperatures regularly peaked above 70 degrees until the end of August, which starts to get dangerous for native trout species.

Grayling, westslope cutthroat and bull trout need colder, clearer water than nonnative trout such as rainbows or browns. But even rainbow trout start to suffer in water hotter than 68 to 70 degrees because warmer water carries less oxygen. If a fish must then fight at the end of a fishing line and spend a minute or two out of water while the angler takes a picture, it's more likely to suffocate even if it's returned to the water. So FWP starts restricting the fishing if the stream temperature peaks above 73 degrees for more than three days; first with hoot-owl closures during the afternoon and then complete closures if conditions worsen.

Conditions were bad this summer in the Big Hole - only in the past month have flows inched up to around 400 cfs and temperatures stayed below 60 degrees, which is about where the river should be for this time of year.

Closures aren’t popular but they’re put in place to protect trout populations so anglers can enjoy them next summer. Without such restrictions, many more fish would die and populations could crash.

This year saw the FWP commission close a river for a completely different reason: disease.

In mid-August, when dead whitefish started washing up on banks of the Yellowstone River, FWP biologists started surveying the river to ascertain the extent of the problem and the cause. While whitefish were strewn from Yellowstone National Park to Big Timber, the greatest mortality, including a few other species, was found on the stretch between Emigrant and Springdale.

Biologists determined the fish were dying from a parasite that caused proliferative kidney disease. Low flow and high water temperatures in the Yellowstone River exacerbated the effect of the parasite by stressing whitefish, reducing their ability to fight the disease.

“Commonly, we don’t see fish health issues affecting fish to this scale,” said Region 3 fisheries biologist Travis Horton.

Similar outbreaks occurred recently in Washington, Idaho and Oregon. The parasite is not native to Montana, and biologists believe it was introduced to the Yellowstone only recently, probably due to unclean boats.

On Aug. 19, FWP commissioners decided to completely close the river in order to reduce stress on the fish and to keep boaters and fishermen from spreading the parasite to fish in other rivers. By then, about 4,000 whitefish had died.

On Sept. 1, the commission began reopening short stretches of the river where fewer whitefish had been affected. Dead fish were still turning up in the middle sections so they remained closed. By Sept. 22, it appeared no more fish were dying and the remaining sections were opened to both fishermen and boaters.

Closing the river was like putting Yellowstone’s trout in quarantine. Had the commission not acted, parasites might have been able to travel on fishing rafts or wading gear to other rivers, and dead fish may have littered the banks of the Madison or the Gallatin.

In September, FWP Operations Chief Paul Sihler told the legislative Environmental Quality Council that proliferative kidney disease is worse than whirling disease so he didn’t want it to spread.

“We also wanted to do everything we could to increase the survival rate of the fish that had been infected because we know a resistance develops. The thing that we could control was stress on fish,” Sihler said. “This was the biggest die-off we’d ever seen in a cold-water river. The agency had to be careful.”

But closing the river for two to four weeks meant the outdoors economy took a hit in the Paradise Valley. The Institute for Tourism and Recreation Research at the University of Montana calculated that Park County businesses lost between $360,000 and $524,000 during the closure. UM economist Jeremy Sage pointed out that FWP’s decision to close the upper Yellowstone River was based on reducing the potential future impact to Montana waters, fisheries and the overall economy. Had more rivers been infected with the parasite, the cost may have been greater.

But that’s not how some legislators saw it.

Rep. Kerry White, R-Bozeman, questioned the commissioners’ authority to do an emergency closure of the river if it isn’t a matter of public health.

Legislative legal expert Helen Thigpen said the commission gets its authority from two laws that allow closures to be put in place for reasons other than public health and safety.

“(The second rule) allows the commission and FWP to adopt rules to protect the resources specifically as they relate to fishing here. So it’s broader than temporary rules to protect public health and safety,” Thigpen said.

White countered that the first rule, which allows emergency closures without 30 days of notice, mentions only public health. Any other reason would require the month of public notice.

“My only question is if it was an emergency closure and the reason for it,” White said. “I’m just requesting something from the department under what authority they did this.”