Hop-Spotting: Fly Fisherman's 2024 HopperCast

Hopper season hits a little different than other insect occurrences. Different and often more knowable factors are available to predict grasshopper populations, as many ag agencies prognosticate so that farmers can appropriately prepare. Aquatic insect hatches sometimes have predictable elements, but on the whole, are much more enigmatic.

So what should we expect this hopper season?

Western U.S.

According to our sources… envelope please … It’s time to buy foam and rubber legs!

But before you withdraw money from your retirement fund, let’s take a look at the map as indications are that the biggest outbreaks will be localized, and not entirely in trout country. But before you get discouraged by that, remember that lots of fish will eat grasshoppers, including many warm-water predators like carp and pike.

According to the United States Department of Agriculture, Agriculture Research Service 2024 Rangeland Grasshopper Hazard parts of Montana, Colorado, Idaho, and Oregon appear to be the hot-spots.

“Right now there’s no indication on any of these weather patterns I’ve seen right now, including cold weather, that indicates that's going to be sufficient to turn the tide on some of these grasshopper populations,” Gary Adams, State Plant Health Director at USDA-APHIS, said in a Montana Public Radio story.

But a cold and wet second half of spring might have put the kaibosh on the early hoppers in certain areas, potentially stunting segments of the overall hatch. Several slow-moving storms produced valley snow from early May into mid-June in Western Montana and elsewhere. So how it will play out is a bit up in the air.

Some specific locations to check for 2024 hopper fishing, according to the map:

Trout

• Mainstem Flathead River in Montana
• Marias River in Montana
• Black Hills around Sturgis
• The Arkansas River near Pueblo, Colorado
• The Bear River and Blackfoot River in Idaho
• The Elk and Yampa rivers in Colorado
• The Yellowstone River around Billings, Montana
• Oregon’s Imnaha River

Other Hopper-Eating Fish

• Brownlee Reservoir in western Idaho
• Snake River around Idaho Falls, Idaho
• Lower St. Vrain Creek and Lower South Platte in Colorado
• The Yellowstone River around Billings, Montana
• Lower Yellowstone River around Miles City, Montana
• Fort Peck Reservoir and the middle Missouri River in Montana (an area where fishing writer John Holt once wrote about northern pike that would leap to grab small birds out of the air)
• Salt River and Theodore Roosevelt Lake near Phoenix

Canada

North of the border appears to have a similar forecast.

“We had grasshopper development almost two weeks ahead of normal in 2023 because of that hot start in May,” Meghan Vankosky, a field crop entomologist with Agriculture and Agri-Food Canada said in an agcanada.com article. “That meant that by June 15, we had adult pest grasshoppers on the prairies. That has not happened in over 35 years. I work with people who have been working on grasshoppers their entire careers… and they’ve never seen adult grasshoppers in June. That’s not good.

And if 2024 sees dry conditions similar to 2023: “2024 is looking to be unfortunately even worse than 2023 in terms of grasshoppers,” she said.

Some of the same locations that had good hopper in 2023, like the Old Man and Bow rivers and Peace River, are again potentially poised for exciting Augusts and Septembers for fly anglers.

While we do not necessarily appear poised to have an all-time summer of hopper slurping, there’s plenty of reasons for hope at some major trout-fishing areas. And as always, you gotta go to know.

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Josh Bergan is Fly Fisherman magazine’s digital editor.

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