Introduction to Fly Fishing Montana in Early Summer
Fly fishing Montana in early summer is ideal for many visitors, though it’s also the busiest season. This period, which runs from late June through late July in warm, dry years and from the beginning of July into early August in cool, wet years, is the prime tourist season in the entire Rocky Mountain region. The Yellowstone area is no exception. Both general tourist traffic and angling traffic can be intense, especially on famous rivers like the Yellowstone.
This season sees the most consistent weather and water conditions of the entire year, as well as the most consistent fishing and insect hatches. That said, your chances for truly epic fishing are probably better earlier or later in the year, particularly if “epic” for you involves a lack of fellow anglers. In other words, fly fishing Montana in early summer usually produces a 7 or 8 out of 10 almost every day for numbers and size of fish, though a 1 in terms of crowds on famous water, while earlier or later in the year you might get a 10 or might get a 2 in terms of fishing quality, and the crowds are much less of an issue.
Besides the crowds, there’s one further deterrent to fly fishing Montana in early summer: bugs. This is by far the worst point of the year for biting insects. Both mosquitoes and biting flies can be huge problems, particularly on cloudy, calm days following wet winters. Be prepared to wear long sleeves at all times while fishing (the new technical lightweight fabrics are good), and you may even need a head net during particularly bad years.
Weather and Water Conditions
As long as you can tolerate heat, early summer weather conditions are the most pleasant of the year. Daytime highs range from the 60s to the 90s, depending on elevation and whether we’re in the midst of a cold spell or not, while nighttime lows range from the 40s at high elevation to the 50s or low 60s at lower elevations. Highs in the 80s and 90s are pretty common except at upper elevations. Brief afternoon thunderstorms are possible, but prolonged rains are rare. Most days will be sunny or partly cloudy throughout the day. That said, you still want a light layer and a rain coat. Though it is possible to wet-wade on almost all waters during this time, I still recommend bringing waders if you have room in your luggage, because we do get occasional cold spells when waders make the difference in staying comfortable or being cold.
Water conditions are likewise at their best of the year: high enough that all rivers lacking geothermal inputs save the Lower Madison remain cold and have hungry fish holding tight to the banks, but low enough that all are almost always out of runoff by July 10 at the latest (June 25 to July 5 more common). With the exception of the Missouri River during dry years, weed growth is at worst an occasional annoyance, and most of the time they won’t be a factor at all. Note, however, that most freestone rivers and even tailwaters following wet years do typically still run high enough that it can be physically challenging wading and getting around the banks, particularly on rough rivers like the Yellowstone, most particularly before the middle of July.
At the beginning of this period, the best fishing flips from the Madison River drainage inside Yellowstone Park and the Missouri and lower Madison River drainages outside it, as well as assorted area lakes, to literally everywhere else. The Yellowstone drainage including its tributaries inside the Park (Gardner and Lamar) and outside the park (Boulder and Stillwater) are our top fishing and guiding areas for the remainder of the season. The Missouri also remains good at this time. The Firehole and entire headwaters area of the Madison inside the park turn off at this time due to high water temperatures and are not good again until fall.
The following options are particularly noteworthy at this time, some of which are right at maximum day-trip range from our base in Livingston: The Yellowstone River (note that the backcountry section upstream of Yellowstone Lake and a stretch of a few miles immediately below Yellowstone Lake do not open for the season until July 15), the Lamar River and its tributaries, the Madison River from Hebgen Lake to Ennis Lake, the Gallatin River upstream of Four Corners near Bozeman, the Gardner River, the Boulder and Stillwater Rivers, the Missouri River “Land of Giants,” and most small streams, including the Paradise Valley spring creeks, which see their best hatches of the year during the first half of July.
My favorite fisheries in early summer are the Boulder River for float-fishing and the Yellowstone River in its Black and Grand Canyons for wade-fishing. Both offer excellent dry-dropper fishing at this time, without the crowds of some more famous and easier-access waters. Float sections of the Yellowstone River between Gardiner and Livingston are also very good, except on crowded weekends and the Fourth of July. In July the Yellowstone typically offers a mix of smaller trout on dry-dropper combinations and larger fish on dead-drifted streamers and nymphs.
Tactics for Fly Fishing Montana in Early Summer
This is prime dry fly season, beginning with the Salmonfly (Giant Black Stonefly) and Golden Stonefly hatches. On steep, well-oxygenated sections of river with large cobble or boulder-strewn bottoms, these hatches are the highlight of the angling year. This hatch of insects as long as your finger is most famous on the upper Madison and Yellowstone Rivers, but it also pops up in shorter sections of the Gallatin, Lamar, Gardner, Boulder, and Stillwater Rivers at this time. Note that the Lower Madison’s hatch occurs earlier in the year. Most places this is a brief hatch, no more than a week, but both nymphs and dries drive the fish nuts. On the Yellowstone inside Yellowstone Park, the hatch can last in spotty fashion through the entire month of July.
Many other insects also begin hatching in late June or early July, and most years hatches stay strong at least through July and sometimes into early August. On steep, broken sections of stream, it’s often best to use attractor dry flies such as Wulffs, Stimulators, Trudes, and my Clacka Caddis to approximately match many insects at once, usually with an attractor nymph dropper or even a second, smaller dry trailing the first. On flatter streams, including the meadow sections of streams in the Lamar Drainage, much of the Madison, the Missouri, and especially the private spring creeks, it’s usually better to figure out which specific insects the trout are keying upon and to match these exactly.
Besides the Salmonflies and Golden Stoneflies, important stoneflies during this period include the smaller Yellow Sally and the tan and black Midnight or Nocturnal Stone. These insects are generally only important on steep rivers and begin hatching as the other large stoneflies are petering out in mid-late July.
Caddisflies hatch from all streams, but are most important on steeper and more-broken streams. They typically draw the most action in afternoon and evening, though egg-laying caddis are possible in the mornings and caddis larvae and pupae (or attractor nymphs that can “push these buttons”) can work at any time. Most caddis that hatch during this period range from #12 to #16 and are tan to brown in color. The tiny black “Micro Caddis” are seldom important.
Mayflies are common on all rivers and on smaller streams that have gravel bottoms. They are more and more important the flatter the stream gradient. Common mayflies in the summer are Green and Gray Drakes, Pale Morning Duns (PMD), and a variety of smaller and less-important species. Of these, the PMD are most widespread. They are small and pale yellow-olive-gray. The Green and Gray Drakes are most common in Yellowstone Park. There are many species which look pretty similar, ranging in size from #10 to #16. All are varying shades of gray and olive, with faint yellow or dark brown markings on some.
All mayflies hatch most abundantly from sometime in early-mid morning until early afternoon. There are sometimes secondary hatches in late evening. Egg-layers can be found in late evening or early morning. These are seldom important. One exception is on the Missouri River, where the tiny black Trico mayfly is most common early in the morning, and for which the egg-laying stage is critical. As with caddis, mayfly nymphs can be important everywhere and all day long, but they’re most important on flatter streams rather than steep rivers or mountain creeks.
Streamer fishing is often overlooked in early summer, but it can be very good at times. This is particularly true of hike-in sections of the Yellowstone River and on the Paradise Valley section of the Yellowstone outside the park. Inside the park, stripping streamers is best. Outside, it’s usually more effective to fish them on a dead-drift.
Terrestrial insects, including grasshoppers, ants, beetles, and crickets on all waters, and the spruce budworm moth near evergreen trees, begin to work sometime in this period. They start earlier in dry years and later in wet years; they are always most important later in this period and on into late summer.
Expect to find fish in fast, shallow water in early summer. Water temperatures are usually optimal (high-50s or low-60s), flows are powerful in the middle of the river, which pushes fish to the banks, and food is abundant, meaning the fish can hold in fast water and still get plenty to eat to make doing so worthwhile. All of this encourages fish to hold in relatively fast, shallow water, even in little pockets in white water. You will seldom find big numbers of fish in slow, deep, walking-speed water at this time, though big brown trout in particular like to hold in fast, deep water preying upon sculpins and stonefly nymphs. These big boys are usually in the first deep water off the bank, especially when there are vertical shelves near shore.
Who Should Consider Fly Fishing Montana in Early Summer?
Early summer is an ideal time for all anglers save those who don’t like crowds (of general tourists and of anglers) and can’t handle biting insects. It’s probably the period that makes the most sense for your first visit to the area, for a variety of reasons: the consistent fishing, the good dry fly fishing, the nice weather, the wide variety of places to fish, and the ease of finding accommodations provided you book ahead of time (since every place to stay is open at this point of the year).
It’s important for me to note that early summer is particularly good for beginning fly anglers, or those with beginners in the group, due to the wealth of small stream opportunities that fish well at this time and can produce plenty of fish for even rookies.
Anglers interested in aggressive hikes, particularly backpacking trips, might want to hold off until late summer. This is particularly true in wet years. The basic reason for this is the potential difficulty in stream crossings since waters are still dropping from runoff during this period, even though all streams are usually low and clear enough to be fishable.
As I’ve noted several times already, crowds are grim at this time of year. This is particularly true on roadside rivers that offer large fish: the Madison downstream of Hebgen Lake, the Lamar River Drainage, and portions of the Yellowstone during its Salmonfly hatch and on weekends after the hatch is over. Soda Butte Creek is often the most-crowded stream within a 500-mile radius at this time, for example. If you don’t like crowds but are up for a hike, don’t mind small streams and small fish, or are planning to float (with the exception of a Salmonfly hatch), you can still find solitude. If you are mobility-impaired but don’t like people, even the bad places to fish near the road might well be too crowded for your taste.