Written by Bob Linsenman 7:26 pm Fly Tying, Midwest, Trout

Au Sable River, MI

The Trophy Water

My father first took me to the Au Sable on my 10th birthday, deeming me strong enough to wade with him at Perry Creek Flat, one of the wide, calm, slow-water pools on “the big river,” downstream from Mio. We entered the water at a shallow spot on the north bank and waded out to within a short cast of several rising fish. There were many bugs in the air that early evening, but I don’t remember if they were caddisflies or mayflies. I do remember a nice slurp where my little Adams had been, then a hard pull and several wild leaps. The fish was a rainbow of about 12 inches, a true giant to me, and the biggest of four I caught that glorious day in 1953.

Through subsequent decades this big-water stretch of the Au Sable was managed with various gear and creel rules as an experimental or research section of the river. Size limits, creel limits, and allowable terminal tackle were varied, but opening and closing dates remained the same as the state’s general trout-stream regulations until 2011. Instead of opening on the last Saturday of April and closing on September 30, the “Trophy Water” stretch from Mio to McKinley opened on April 1 and remained open year-round. Additionally, tackle was restricted to artificial lures only, and strict harvest limits on the size and number of fish of different species were coordinated to the time of year. As a result, anglers must now check and study the trout regulations carefully.

The Trophy Water designation speaks to the desired goal of the regulations and, just as important, reflects ideal conditions for rapid and significant trout growth in this section of the Au Sable. The combination of gravel, sand, rocks, shaded undercut banks, and cold-water springs through the repeating pool-riffle-pool progression creates a nourishing habitat for aquatic insects of all types, as well as crayfish and forage fish such as sculpins. This food-rich environment grows numerous big trout quickly. Brown trout seem to do particularly well, and true trophies in excess of 20 inches are abundant and regularly caught on dry flies, nymphs, and streamers. The absolute giants—in excess of 24 inches—are most often caught on large streamers.

Through time, all rivers change from the impact of floods, ice-out scours, drought, and fishing pressure, and the Au Sable has not been immune to change through the past 60 years. But from my perspective, a happy constant on this stretch of the river has been very good fly fishing throughout the regular season. To be honest, no one knew what the results might be when the water opened to year-round angling. Locals hoped for good fishing in the early spring and expected fine fishing in the late fall, but had no idea what the dead of winter would bring.

All of April exceeded expectations. Giant browns were caught seemingly every day on a variety of medium (3- to 4-inch) to very large (6- to 9-inch) streamers. The more experienced streamer anglers knew enough to slow their retrieves in the very cold water, and they had the best results by far.

From May through September the Trophy Water went through several fishing phases, based on hatches and water temperatures.

October and November fished about as everyone had hoped. Angling was usually excellent and surprisingly unaffected by bright, cloudless skies. From December on through March, I thought very cold water temperature would slow the metabolic rate of brown trout to a crawl and greatly reduce angler success, but I was dead wrong. I caught big fish—or at least some followed my streamer—on nearly every float, despite bitter, freezing temperatures. Best results were with medium-size streamers in natural colors fished slowly. A 3- to 4-inch olive, wool-head Sculpin was good all winter.

The Au Sable at the small town of Mio usually runs about 1,100 cubic feet per second (cfs), much faster than the more serene and comfortable 100-cfs flow 30 miles upstream at Grayling. This is big water that can be dangerous to the careless or foolhardy wader, but it is safe to wade and fish in many places by just about anybody with an IQ above room temperature. If the water looks too deep, it is. If the current feels too strong, it is. Flow rates up to about 1,300 cfs are acceptable for wading in most locations, but anything near 1,400 to 1,600 requires extreme caution. A flow rate of more than 1,600 cfs requires a boat.

The Trophy Water is divided into two major stretches, with only slight differences in water types over the course of each 7-plus-mile section.

Mio to Comins Flats

The stretch between Mio and Comins Flats begins at the public access and canoe/boat launch immediately downstream from the river bridge in Mio. This run of river flows approximately 8 miles to Comins Flats, the site of a large canoe/boat-launch facility with outdoor toilets and ample parking for vehicles with boat trailers. Public land in the Huron-Manistee National Forests borders almost all of this section, providing excellent river access for wading anglers.

This upper section of the Trophy Water is blessed with alternating micro habitats ideal for a wide array of aquatic insects, so hatches are typically strong, reliable, and productive. Mixed sizes of gravel, larger rocks, sand, and smaller pockets of silt and clay are home to various Blue-Winged Olives, Hendricksons, Sulphurs, Mahoganies, March Browns, Brown Drakes, Isonychia, numerous Cahills, and the beautiful Ephoron leukon. Some Hexagenia inhabit this section, but not as many of them as in the other nearby stretches. In addition to the mayflies, caddisflies abound, and stoneflies help nourish the trout for most of the year. The Pteronarcys dorsata (Giant Black Stonefly) hatches in late evening in June and early July. This bug is as big as the western salmonfly, and although it doesn’t appear in the same densities as the salmonfly, it certainly does excite the larger Au Sable trout, which slurp, crash, and wallow out there in the dark.

The same environments that nourish insects sustain ideal conditions for crayfish, dace, shiners, chubs, sculpins, and baby trout. Of these, crayfish, sculpins, and trout are the preferred prey species for the Trophy Water’s larger trout. Although browns longer than 25 inches are caught every year on dry flies (usually Hendricksons, Brown Drakes, Isonychia, and larger stoneflies), the majority of the real trophies in this section are caught on streamers. Sculpin and crayfish patterns work all year, but at certain times a fly imitating a juvenile trout is an absolute requirement for success.

Michigan’s Department of Natural Resources (DNR) stocks the Trophy Water with thousands of rainbow and brown trout between 5 and 8 inches long in late April or early May at the accesses at Mio, Comins Flats, and McKinley Landing. The stocking event rings the dinner bell for the river’s largest fish, which congregate at or near the stocking sites and ambush the little fish mercilessly. To be successful, fly anglers must match the hatch with large streamers that look like baby rainbows and browns. These flies should be at least 4 inches long, use colors matching small rainbows or browns, and have big eyes.

The most convenient wading access points in the upper stretches are reached from McKinley Road (County Road F 32) on the north side of the river. The main exception to this is the Mio access, which is on the south side, just below the County Road M 33 bridge. Happily, these sites have good fish populations and are wadable with just a bit of common sense.

Loud’s Rest Stop is the first access point downstream below Mio. It has a small parking area and vault toilets. The Au Sable Loop campground is next and has five campsites and a path to and along the river. River Dune is just downstream from the Loop campground (about 150 yards) and fronts a beautiful, highly oxygenated riffle that bends into a wonderful big-fish pool known as The Eagle.

Less than 1 mile downstream, the Au Sable River Scenic Overlook sits on a high bluff above a large curve in the river. Just downstream the river straightens into a lively riffle before turning left at the head of Perry Creek Flat. This water is outstanding dry-fly water, especially at dusk during spinner falls.

Meadow Springs is next. This site requires a short hike from the small parking space. It is designated as a remote or walk-in/boat-in campsite and has vault toilets. The pool at Meadow Springs is another superb dry-fly area.

Finally, Comins Flats is the last site for easy park-and-walk wade-fishing in this section. It is probably the most popular spot in the Trophy Water for wading anglers. It is wide, relatively shallow, easy to wade, and densely populated with small to medium-size trout and a few large predators. Comins Flats is 8 miles by river below Mio and 5 miles by car along McKinley Road.

Comins Flats to McKinley

Spanning 8 river miles (about 5 road miles), the Comins Flats–to–McKinley reach is similar in character to the upper stretch but has fewer curves and more slow-water sections. Additionally, it flows through an area of private riparian lands with numerous cabins and homes on both banks and provides fewer easy drive-in access points. Still, the fishing is excellent and the “cabin stretch” is surprisingly good.

The big pool and curve immediately downstream from the boat ramps at Comins Flats often hold several trophy-size browns that are hunting for a substantial meal of baby trout. The next access below Comins is at the riffle and left bend below the spot where the river comes up tight to McKinley Road, a few hundred yards below the road to Comins. There is a small parking area here.

Davis Landing is about 2.5 miles farther east, off McKinley Road. A sign and a very large letter “B” on a tree at the access road indicate the way to the water. Davis Landing has a wonderful riffle that smooths out into a great curving pool. Dries, nymphs, and streamers are all productive here.

The next two access points are big-fish havens but require more careful wading due to depth and current. East (downstream) by road a short distance from Davis is a sign designating a scenic overlook on the right, and just past the sign is a narrow parking spot and a set of stairs down to the river. This site, called Werewolf Bend, is a great, if a bit spooky, place to fish in the late evenings. The next good wading spot is at US Forest Service Road 4832, a small two-track trail that runs about 0.25 mile to a parking area on a bluff over the river. This area, which is called the Bear Hole, offers very good nymph and dry-fly fishing, but wading here can be a little dicey if the water is running high.

Lastly, McKinley Landing, the downstream limit of the Trophy Water, provides a boat launch with vault toilets. Because it’s a stocking point, there are often large predator trout nearby.

The hatches in the lower stretch are virtually the same as those in the upper stretch, with one notable exception: the slower runs just above McKinley are rich with silt and support larger populations of Hexagenia limbata nymphs, which occasionally produce fishable numbers of emerging duns and falling spinners. These same slow-water stretches produce exciting and challenging fishing to larger cruising rainbows and selective, snooty brown trout during most mayfly spinner falls, but I like Hendricksons, Isonychia, and Brown Drakes most. This part of the Au Sable produces quite a few giant P. dorsata stoneflies, and often you will hear a solitary crushing rise followed by total silence—no more heavy rises, no gentle slurps. This is usually a clue that a big fish has eaten a dorsata, a mouse, or perhaps a smaller trout. Big, dark Stimulators and deer-hair mouse patterns are especially productive on the darkest nights.

Crayfish, baby trout, and baitfish, especially sculpins, are every bit as important here as upriver. Streamer anglers do well most of the year between Comins and McKinley, but the best fishing is early, through May, and late, through December. High water and dark, ugly days are best. Fish the whole river. Very often the biggest trophies lurk on the inside of big sweeping curves, where they can rest out of the heavy current and whack unwary prey with less effort when the river is running high and fast. The cabin stretch supports huge numbers of crayfish, and a little, nondescript pattern called the Trick or Treat is a killer in this area. When wet, the fly looks very much like a small crayfish, and it produces best when fished in short hops near the bottom. The Ditch Pig is another streamer that produces big fish throughout the Trophy Water. It is a three-section articulated fly with hooks in the first two sections only; the third-section hook is clipped off at the bend. The Pig seems to represent an eel, a lamprey, or perhaps a giant night crawler. Regardless, its slithery, shaky action often brings heavy strikes from the larger trout in the river.

Techniques and Tips

To enjoy consistent success on the Au Sable Trophy Water, particularly with large trout, you need to adapt your techniques to match the peculiarities of the fishery.

Dry-fly action can be bank to bank, depending on your location. When several fish are rising in proximity, study the rise forms carefully. The largest fish doesn’t always make the loudest slurp and rarely makes the showiest rise. Watch for an upwelling, or bulge, of water as the insect disappears. The larger the bulge, the larger the fish (usually). Try to present to the largest fish first if at all possible. Your first cast represents your best opportunity, so study speed and drift line in the current carefully before casting.

The biggest fish are incredibly spoiled by a rich diet and become extremely selective as they grow larger and wiser. Rarely will they move left or right, even a few inches, from their feeding lanes. The exception to this is when a big fish is selectively feeding on crippled duns. When you see several perfect duns with upright wings like mini sailing boats drift over an active trout without being eaten, and then see that fish move right or left a few inches to eat, it is a good bet a crippled dun was targeted.

Nymph and wet-fly strategies are not much different here than in most rivers. I recommend a two-fly rig on most days. Usually an attractor nymph, such as a beadhead Prince Nymph, is best as a dropper, with the nymph of the prevailing aquatic insect as the point fly. Very often using the bug du jour with a soft hackle as the trailing fly is the most effective combination. A technique that has been good to me is dead-drifting with a slow, pulsing lift of my rod tip as the rig swings through its downstream arc. Riffle water is best by far for nymphing throughout the Trophy Water.

Streamers produce the Au Sable’s biggest trout and have developed a large and passionate fan base through the years. Streamer loonies (I count myself in that group) chuck flies from 2 to 10 inches in length in every imaginable shape and every conceivable color combination. For some reason, perhaps angling pressure, these brown trout are fickle when it comes to color preference. One day they want yellow, and only yellow. The next day they will not spit on yellow, but will happily eat olive. The next day the right color may be tan, black, white, chartreuse, or yellow again. It pays to experiment, to change colors frequently until you find the day’s preference. Fishing two smaller streamers in contrasting colors in tandem speeds up the process but will challenge your casting skills. If the trout don’t respond to a color within 15 or 20 minutes, it’s time to change. A good basic rotation is yellow, olive, white, black, tan, chartreuse.

Size does matter. Although very large trophy trout eat smaller streamers, the bigger flies seem to fool the alpha predators most often. I think this is because the larger streamers trigger two synapses: they are the right size for a satisfying meal, and they are big enough to elicit an aggressive territorial response to an invader.

The best streamer fishing is generally from October through early May, but fishing can be electric any day of the year when clouds and rain raise water levels and excite the big ones. Excellent hatches produce fine dry-fly and nymph angling from late April through June and again in late August and September. Watch water temperatures during the summer. If they reach 70 degrees, it is dangerous for trout, and you should fish the fine lakes in the area for bass and panfish until the river cools. Midsummer weekends are problematic for anglers due to excessive recreational canoe traffic. To avoid the aluminum hatch, fish early in the morning or late in the evening.

Although the Au Sable, like all streams, has seen changes through the decades since I caught that memorable 12-inch rainbow, this historic river continues to provide consistent fly fishing—and consistent excitement—year after year. It’s the potential for big, exciting fish that keeps anglers’ attention, and only time will tell just how, or if, the recent shift toward trophy management affects the fish population.

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Bob Linsenman
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Last modified: August 26, 2022
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