Hot and Heavy: August Hoppers and Tricos in Montana
By Sam Lungren

What’s the opposite of “finesse” as it relates to fly fishing? Power? Water flogging? Brute force?

Trico mayflies and grasshoppers dominate August fly fishing in Montana, but imitating the two insects might as well be different sports. Tricos are damn near microscopic, usually in the size-20 class or smaller, requiring a dainty, exacting presentation with hard-to-see wisps-on-a-needlepoint. It’s an infamously aggravating hatch to fish effectively—though the cognoscenti can’t get enough of it.

Hopper fishing embodies whatever is the antonym to all that. First of all, the bugs get huge—sometimes occupying the #4 to 8 range. And, as terrestrials, they genuinely hate being on the water when the wind or a wayward hop lands them in it. They splash around like a pigeon in a puddle. They struggle mightily to swim and flutter and flop their way back to shore, often only to succumb to the wetness on their wings dragging them to death by drowning or brown trout jaws. Topwater frog fishing for largemouth bass is a better allegory than those delicate and refined descriptors we often reserve for dry-fly fishing.

Still, these dichotomous fishing methods occupy many of the same days on the same water in the same hot season in the Treasure State and other Northern Rockies trout streams. Rigged for both, you can stay stocked on surface eats from dawn to dusk while many other anglers have switched to bass, carp, snorkeling, or air conditioning.

Male tricos display a black body while the females are more yellow. Look closely at bugs on the surface to make your call. Photo by Nick Price.

Basics of Trico Fishing

Mayflies of the genus Tricorythodes are present in many trout streams from the East Coast to the West, but you might be excused for having ignored them entirely. They’re hard to see for one, and possibly easy to confuse for a midge if you do. They’re known for occupying slower water than many of their larger Ephemeroptera cousins. According to Montana Fish, Wildlife and Parks, Tricos, “increase in abundance when streams become silted, dewatered and warmer.” The females l hatch in the heat of the late morning from late July sometimes until October under high sun, when most other self-respecting aquatic insects are still hiding in the bushes or substrate. Mating and the spinnerfall may be done anytime between mid morning and mid-afternoon. But, trout may continue eating spent bugs well into the hazy northern dusk.

Guides often push right past a Trico hatch with clients in the boat, putting preference on hoppers and other easier-to-see bugs. You’d do the same if you were shoveling water for noobs every day. It’s tough to get right, but the rewards are well worth the effort. All of the best anglers I know are magnetically attracted to a challenge.

Side channels can provide great habitat for hopper and trico-eating trout.

How to Fly Fish a Trico Hatch

You might quickly see why this challenge is so attractive. It’s not uncommon to witness rather big fish snorkeling tricos in a relatively predictable manner. The trout might refuse your first fly. It might refuse your second. The third may go completely unnoticed. But if you bring the proper time and patience and bag of tricks, you can refine your presentation and continue to work that fish for hours. Trout being trout, they’ll make a mistake eventually. Be ready for when that happens.

Sometimes though, Trico hatches are more about hacking through the chaos than presenting an individual fly to an individual fish. When that prolific “blanket hatch” occurs, trout sometimes eat them in a style more akin to a baleen whale, hoovering dozens off the surface at once. But they won’t want to shift off their feeding lane or rising pattern for any imitation that varies from the norm. It’s incumbent on the angler to present precisely on the seam where the target fish is rising. An inch too short or too far and it won’t get touched. Mind the cadence with which the fish is rising and time your shots when you think a nose is coming up.

While you can fish upstream to Trico eaters, it’s usually more effective to present quartering downstream in such situations, whenever the river allows. This can mitigate running the leader or line over spooky fish, showing them the fly before the mono. In a driftboat, it helps to set the anchor softly and well upstream of the rise forms. You can always release more scope in the line to get closer. When wade fishing, work your way close to the riser softly, observing the fish’s behavior, location, and timing. Don’t be in a hurry. Make deliberate, accurate casts and don’t be afraid to rest the fish after you’ve made a couple shots.

Best Gear and Flies for Trico Fishing

This is 3- and 4-weight territory, providing precision casts with a minimal splash. A 5 will work if that’s what you have, but make sure to feather your landing to mitigate fly or line slap. Long leaders are a must for the famously selective trico eaters, so start thinking about 10 or 12 feet or more, culminating in 6X or 7X tippet. Take your time and rig with intention, because there is little room for error.

It’s best to patronize a local fly shop if you really want to do well with Tricos. It might not be everyone’s favorite emergence, but they’ll likely know what size hook and construction of materials the local fish prefer. That might be as big as a #18 with a full parachute post on some Eastern and Midwestern streams, or as infinitesimal as a #28 on Montana’s Missouri, Clark Fork, or Bighorn. It’s helpful to come prepared with a strong selection of duns, spinners, cripples, and spent-wings in various sizes and experiment your way to success.

Just the phrase “size 28” is probably enough to make most experienced anglers’ eyes cross. But once you see a real blanket hatch of Tricos coating the slick surface of a wide tailwater, with trout happily mowing through the horde, you’ll get why the local diehards all carry magnifying-glass lenses and 7X tippet. Like most things fishing, it’s fun precisely because it is hard.

Grasshoppers vary widely in size and color. It’s difficult to beat brown and tan imitations.
Photo by Nick Price.

Basics of Grasshopper Fishing

Now, forget everything I just told you about Tricos. Take a deep breath. Set down the 4-weight and pick up the 6.

While Trico mayflies may be an acquired taste, everyone loves hopper fishing. It can be very hit or miss, but when that explosive hit does come, damn is it hard not to war whoop.

The fishing couldn’t be more different, but it’s exactly those differences that make hopper and Trico fishing so strangely compatible. July and August Tricos often hatch in the morning, while grasshoppers generally become more active in the afternoon. Fishing a Trico is all about accurately delivering right on the nose of a specific, actively rising fish—but it’s unlikely you’ll see trout sipping hopper after hopper. That method is all about prospecting and covering water, looking for a couple hungry players. Also, the delicacy and finesse of Trico fishing is aided by a dead or slight breeze. In contrast, grasshoppers live in the grass and bushes along the banks, so a little wind gets for getsthem in the water. Trout have to be aware of the naturals to eat the unnaturals.

Montana is home to the northern grasshopper, or northern spear-throat grasshopper, Melanoplus borealis, a member of the short-horned grasshopper family. It’s one of more than 11,000 grasshopper species worldwide, an order of insects thought to date back to the early Triassic period—about 250 million years—likely demonstrating the durability of their design. The armored insects that survive their barrage of predators long will molt five or six times from an egg before they become a fully mature, winged adult. You’ll see plenty of the terrestrial nymphs, flightless but preternaturally capable of jumping, throughout the forests and fields during spring and early summer, but they don’t seem to become of paramount importance to a trout’s diet until sprouting wings and taking to the skies following their final molt, usually sometime in the heat of July. Trout and many other fishes eat them readily until they die off with the first frosts of September and October.

Best Gear and Flies for Hopper Fishing

Hoppers are present at all altitudes, so don’t sleep on that side of the fly box whether you’re in a high alpine lake, wide and slow lowland river, or a creek in between. M. borealis vary widely in size, shape, and appearance, so grab out of more than one bin in the shop. Effective patterns can vary from 1-inch monstrosities to stealthy size 14s, in hues from light peach to jet black.

While anglers sometimes intuitively expect the smaller, less obtrusive patterns to produce more, the opposite can be true. While small may be the call on heavily pressured creeks, the wilds and widths of the lower Missouri and Yellowstone can bear a tremendous amount of pressure without every fish getting educated every day. . Match coloration and pattern as best you can, but don’t be afraid to experiment. While natural tan, brown, or gray are often good choices, pink and orange are very popular too, as are black, purple, and green. Sometimes that matters, sometimes it doesn’t.

Likewise,profile is important—especially on slower waters where the fish have a long time to inspect a hopper. Something low-riding with natural fibers, like the turkey-winged and pheasant-legged Parachute Hopper, may prove more attractive to hot trout in low-angle mainstem rivers where they can take a good hard look at it first. But in quick water, the simple, all-foam Morrish Hopper is a durable, buoyant standby—though it might be the first to go in and back out of circulation on many guide boats. Sometimes something with a little more heft and wing gets a big fish stirred up, not to mention saving on your floatant bill. I also must acknowledge that hopper patterns are big, relatively simple, and about the most fun bugs to tie on your own vise. The naturals have large, powerful red or yellow hindlegs, which provide countless interesting options for mimicry. Creativity can pay big dividends here, because most trout come Labor Day will have seen every commercial hopper offering sold at the closest fly shop.

Even the largest trout can’t resist and perfectly-placed hopper.

How to Fish with Hopper Flies

A 6-weight with a slightly aggressive line head is helpful for rocketing these wind-resistant flies accurately into small pockets between cutbanks or boulders, especially out of a moving driftboat. It’s far more like fishing a salmonfly or other stonefly hatch than caddis or Trico, so don’t be afraid to slap that thing down and ring the dinner bell. Likewise, it’s usually very helpful to provide the bug some action once it’s drifting. You’re not jet skiing here, but you do want to get those foamy or rubbery legs moving. Grasshoppers hate getting wet and fight hard to fly, skitter, or swim back out of it. The trout expect to see them flopping around like a bird in a birdbath, so that motion can be a major trigger. A light horizontal wiggle with the rod tip every few seconds seems to be a good cadence.

If the bug sinks, so be it. Let it ride, so long as you can still see it. The biggest and smartest trout in many streams keep from breaking the surface, making a drowned grasshopper a safer meal. Either sub-surface or on top, practice a slow hook set, as you would with other large dry flies. Trout often swipe or splash or nose or double-chomp a hopper to kill it or confirm its veracity. Set when the fish has actually grabbed and turned—not before—which of course is easier said than done.

Grassy banks are the classic spots for grasshopper fishing for logical reasons that don’t need to be explained here. However, especially on windy days, it’s not uncommon to see hoppers in flight travel 100 yards or more. That could land them damn near anywhere in a river or lake. When streams get low and warm late in the summer, trout often move off the bank and into the deepest, coolest holes in the middle of the flow. It’s better to put the bug where the quarry lies than where it doesn’t.

Speaking of hot weather and water, with drought conditions across the West, bear in mind that we may only continue to have our fun with these lovely fish if we continue to prioritize their health. Montana has frequently placed Hoot Owl closures on many rivers throughout recent summers, closing the fish after noon or after the water reaches beyond 70 degrees. Many anglers practice their own restraint by carrying a thermometer in their pack. I’ve personally had a blast and learned a great deal from snorkeling rivers in the heat of fire season—not to mention bringing home some crayfish to boil. Trico finesse and hopper power can provide hot and heavy fishing, but we owe it to our dance partners to sit down once the water gets too steamy.

It’s hard to not grin wide after a long summer day with tricos and grasshoppers on the water.

Sam Lungren grew up in the rainforests of Western Washington and began chasing the steelhead dragon at age 15. That led him on a lifelong journey in pursuit of other challenging fishes, from Costa Rica to Iceland and across the United States. His professional career has been dedicated to fueling that addiction, editing and writing about fishing, hunting, and conservation at RMEF, Backcountry Hunters & Anglers, MeatEater, and Outdoor Life.