The impact of last year's historic flooding on Yellowstone River's fishing industry

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It's been a year since huge floods on the Yellowstone River wiped out roads in and around Yellowstone National Park. Those floods upended the lives of people who live downstream. Many are worried about what those floods meant for the river's world-famous trout fishery. It's a big part of the local economy. Yellowstone Public Radio's Olivia Weitz visited the river with a fishing guide and has this report.

OLIVIA WEITZ, BYLINE: Matt Wilhelm, a burly Midwesterner who's been guiding fishing trips on the Yellowstone for 20 years, is checking out the river from its banks on a private ranch near the town of Livingston.

(SOUNDBITE OF WATER RUSHING)

WEITZ: Surrounded by snow-capped peaks, he shows me some of the changes last year's flood brought.

MATT WILHELM: That is a new channel. That's a pretty significant channel right there.

WEITZ: When huge amounts of water barreled through here last June, it cut a new pathway through what was grass and cottonwood trees.

WILHELM: There were all sorts of new challenges. It was a brand-new river, a lot of places.

WEITZ: Familiar sandbars are gone. There are new gravel bars and whirlpools to navigate. Woody debris the flooding river deposited overhangs the river, providing new habitat where fish can now more easily hide. Wilhelm and his guiding friends have had to relearn the river. On some of their trips, they brought a chainsaw in case they had to cut through trees.

WILHELM: A lot of people will just breeze past it and not drop anchor. But if you're willing to get out of the boat and explore these channels, you can have some dynamite fishing.

WEITZ: More than 400,000 visitors a year fish while they're in Montana. They contribute about $1.3 billion in spending. Wilhelm guides about 50 clients a year on this river through his Yellowstone fly fishing school. While he's excited to bring them to this new stretch of river, he hopes there are still enough fish to keep his clients happy. The floods hit right after rainbow trout finished spawning.

WILHELM: Those rainbow trout eggs were just hatching, and what I'm worried about is if those fish got washed downstream or if they were injured or hurt or killed or all three.

WEITZ: Scott Opitz, a fisheries biologist with Montana Fish, Wildlife and Parks, says it's too early to say how the floods affected the Yellowstone's fish populations, but he's not expecting devastation.

SCOTT OPITZ: In terms of the fish world, a big event isn't always negative. A lot of times, it can be a really good thing in terms of moving and loosening up that stream bed so that those areas can be used more efficiently for fish to spawn.

WEITZ: Opitz says the fresh rainbow trout eggs were susceptible to damages from the flood, but there would have to be multiple years of losses to really put a dent in the population.

OPITZ: The one saving grace with the Yellowstone and a lot of our other systems in Montana is that those fish aren't restricted to just spawning in the Yellowstone River.

WEITZ: Last year was a once-in-500-year flood event, but Opitz anticipates fish populations will follow historic flood trends on the Yellowstone River. There may be some declines initially, followed by a rapid rebound. Opitz compares what happened with the flood to a wildfire event. There can be some negative impacts, but it's also a reset for the system that later brings rejuvenation. Fly fishing guide Matt Wilhelm says he's excited to get back out on the river this summer and look for fish in some of the habitats the flood created.

WILHELM: There's no prettier place to be than on a river or a lake trying to catch a fish. So just being outside - it's a great way to earn a living and a great way to be outdoors at the same time.

WEITZ: This year the Yellowstone River crested in late May. It will likely remain too muddy for good fly fishing until the end of the month. For NPR News, I'm Olivia Weitz in Livingston, Mont.

(SOUNDBITE OF MAREN MORRIS SONG, "GIRL") Transcript provided by NPR, Copyright NPR.