Out of Bounds

Rivers Like Boiling Caldrons

I hope the weather pattern breaks and we get rain and cooler temperatures soon

By Rob Breeding

I don’t like being Debbie Downer, but summer has sucked so far.

It’s always a bad sign when your trout stream feels like a wading pool in August. When it feels that way in mid-June, however, the apocalypse may be upon us.

So Montana Fish, Wildlife and Parks took action, imposing hoot owl restrictions on some rivers (no fishing after 2 p.m.) and closing reaches of others altogether.

It’s the new normal in the Northern Rockies. Spring gives way to summer a little earlier each year, then the hot season holds off the cooler temperatures of fall longer than it once did. The extended dog daze of summer then take a toll on the charismatic fauna of the region’s trout streams.

One closure is on the Big Hole where I tried to fish last week. Much of the upper Big Hole is high elevation, 6,000 feet or more, where you might expect nighttime freezing temperatures, even in June, would keep the river from warming too much. But it hasn’t been that cold even up high, and the Big Hole is heavily utilized by ranchers.

That upper river, much of it now under fishing restrictions, meanders lazily across the valley floor, shallow and wide. It looks pristine from a distance, but a significant portion of those river flows are irrigation runoff. The process of diverting, spreading, then returning water to the river channel warms and pollutes the waterway, making it less suitable for trout.

So despite the elevation, the upper Big Hole is sort of tailor made for the kind of overheating that shut down fishing on the stretch between Wisdom and Jackson last week. But that’s not the case for the Flathead River system, which even in drought years, usually maintains the chilly temperatures trout need to thrive.

Until last week, when this newspaper reported Flathead River temperatures rose to 61 degrees on June 29, 12 degrees higher than that same date in 2020. More alarming still, the U.S. Geological Survey water data website showed the North Fork Flathead River peaked at 66 degrees on June 30.

To put that number in perspective, FWP drought guidelines allow for closures when river maximum temperatures reach 73 degrees for three consecutive days.

The implications of this are a bit scary if you’re a person like me who enjoys fly fishing for trout in the summer, and maybe more than a bit if you derive your living by guiding folks down rivers so they can fly fish.

My hobby, and that business model, are both built on the concept of catch-and-release. You don’t need to be a biologist to realize there are a lot of people in drift boats and rafts out trying to exercise trout in Montana this time of year. It works because most anglers, and just about every river guide, practices catch-and-release. Trout are caught over and over, but most of the time are returned to the river a little shook up, but otherwise healthy to live and fight another day. 

It’s a great system when river flows are high and steady and water temperatures stay in the 50s and low 60s where trout prefer them. But catching, playing, netting and then releasing a trout back into water more than 70 degrees is an exercise in futility. The fish may look OK when it swims away, but the stress of survival in water that is already too warm for comfort, and even less optimal for recovery, is too much.

Trout pushed this hard go belly up, only later, out of sight and mind for anglers.

I hope the weather pattern breaks and we get rain and cooler temperatures soon. I’ve seen summers saved by the rain gods before, but the long-term trend isn’t promising. If the climate keeps warming, we’re in for a real awakening.

Rob Breeding writes and blogs at www.mthookandbullet.com.

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