Run off is now over on all rivers in Montana. One of our most commonly asked questions is “when is the best time to fish Montana” – well the answer is now! It is pretty hard to go wrong out there right now – every guide is a rock star under these conditions and there are a lot of bent rods and smiling faces on the rivers.
Water levels are slowly dropping on rivers and streams. The snow pack is not completely gone so the flows are still at higher levels and the water temps are still on the cool side. Trout love falling waters and the rising water temperatures are triggering a cascade of aquatic insect hatches. Peak activity this time of year coincides with the emergence of aquatic insects during the hatches. The peak hatch times depend on the fishery, on cold mountain streams, spring creeks, or some rivers that just cleared but still have a lot of snow melt water feeding them the hatches don’t begin until late morning and often run from 11am until 3pm. On warmer fisheries that have already been clear for a while, or ones at lower elevations, the emergence is early in the morning, sometimes as early as 8am and things are wrapped up by lunch time. Make sure you are on the water when the bugs are because that always coincides with the best fishing. If you arrive before the hatch try streamer fishing or deep nymphing. Make sure you have imitations of the insects that are hatching. Depending on where you are this could be pmds, yellow sallies, golden stones, salmon flies, caddis, etc. Also play close attention to the insects on the water at a given time, often PMD’s hatch before yellows sallies for example. On highly fertile fisheries with thick hatches like spring creeks and tailwaters the trout become very selective during the hatch and you must imitate the correct species as well as life cycle of the insect that the trout are keying in on. On less fertile freestone streams it is more of a potluck and the trout will feed more opportunistically. On spring creeks plan on match the hatch but if you are fishing waters with sporadic hatches try big attractor dry flies on top or large streamers down under to move fish farther than smaller patterns. Expect to fishing to slow down abruptly once the insects are gone but you can often continue to pick fish up later in the day. In the evenings there is often another flurry of activity just before dark.
There are no shortage of insects available to trout on our local waters this time of year. If you aren’t paying attention to the insects then you are definitely missing the boat. Aquatic insects are by far the dominate food source right now on most streams and rivers. Expect to see pale morning duns (small size 14 yellow and light grey mayflies), yellow sally stoneflies (size 14-12 yellow), caddis (several species, tan and cream size 16-10 – fast active fliers), golden stoneflies (big size 8 with dark gold body) and even some late salmonflies (giant size 2, three inches long). There are also some different drake species of large mayflies hatching that can excite fish such as brown and eventually green drakes. Make sure to have all stages of the life cycles in your boxes. For mayfly species like the pale morning dun have nymphs, emergers, cripples, duns and spinners. For caddis have larva, pupae and adults. For stoneflies nymphs and adults.
You basically have to determine if you are going to match the hatch or bust the hatch this time of year. When you can see fish actively rising on the surface it is generally best to match the hatch. The same as true before a hatch, nymphing with the imitation of the nymph or emerger that the fish will see later is a good bet. When the hatch starts if fish are on the surface it is best to match the hatch or try a “cripple” or “emerger” pattern behind an adult imitation. If the hatch gets to a blanket stage then try a size or two larger than the natural. If fish are not taking flies off the surface then the nymphing game can be tougher during the peak of the hatch unless you are sight casting. There can be so many naturals underwater that your imitation has beat the odds that are often 100:1 with so many real bugs in the water. If you are nymphing during a strong hatch it is often better to switch to much larger patterns or streamers dead drifted or stripped rather than compete with naturals. Interestingly when a hatch is sparse we flip flop are strategy. On the surface you can still catch fish with an exact imitation but you can often be even more successful with a large attractor fly that will move fish farther. The trout aren’t so keyed in on the natural that they won’t switch gears and eat something even bigger like a fat albert or chubby Chernobyl. When nymphing it is nice to continue to have an exact imitation but consider trailing it behind something larger like a big stonefly nymph, crayfish or sculpin.
Flows are all over the place right now on different rivers. On fisheries that have already dropped significantly trout are already moving into deeper runs for protection but on the rivers with higher flows they are in the safe havens that have slower current speeds like along banks, behind rocks and on the inside corners of bends or slower tail-outs.