One of the most commonly asked questions is "When is the best time to fish Montana?" The short answer is "Whenever you can get here", but the real answer requires some more explanation. Given the vast diversity of waters around the state, the "best" time for each region and even each river is different. One of the keys to a successful fishing trip is choosing the right waters to fit the timing of your fishing. Below is a general guide on what the fishing will be like throughout the season.
March
Although some anglers fish year-round in Montana, the season really starts to get going in March. While March can still be winter, we get our fair share of nice days as well. March is a great time to target spring creeks and tailwaters, as the waters will be warmer than the freestone streams and the fish more active. The Madison, Bighorn, and Missouri are examples of tailwaters that fish well. Most of the fishing will be nymphing, but there will be occasional midge hatches and some early Blue Winged Olives as well. The spring creeks around Livingston, MT see strong midge hatches as well as opportunities to nymph for some larger pre-spawn Rainbows and Cutthroats. In Western Montana, the Skwala hatch presents good dry fly opportunities on the Bitterroot and Clark Fork, though it tends to be crowded. Northwestern Montana rivers are still pretty cold, but the Flathead does offer some opportunities.
April
April sees good nymph fishing on most rivers throughout the state, and warming weather and water temperatures puts the fish on the feed. The tailwaters and spring creeks are still fishing very well, and April is a good month to target bigger fish on streamers on larger freestone rivers like the Yellowstone and Blackfoot. April sees some great hatches of Blue Winged Olives on cloudy days, and towards the end of the month March Browns and Mother’s Day Caddis are hatching. Top choices for the Caddis are the Lower Madison and Yellowstone River. Around Missoula, Rock Creek sees some excellent hatches of Mayflies and Caddis.
May
Strong hatches continue into early May, but as the month rolls along Montana’s freestone rivers and streams will move into spring runoff. Rivers like the Gallatin, Rock Creek, and Flathead will be unfishable until sometime in mid to late June at the earliest. Both the Upper and Lower Madison shine during May, with good opportunities for both float and wade fishing. The Missouri and Bighorn are good options through runoff, as dams keep these rivers clear 365 days a year. The clear water attracts crowds though, so don’t expect solitude. The Livingston Spring Creeks continue to nymph very well, with mayfly hatches on cloudy days. May is also a good month to target lakes throughout the state. The ice will be off and the fish will be hungry. Yellowtone National Park opens to fishing on Memorial Day weekend, and the Firehole is a great option on opening day.
June
Runoff dominates early June, so the best options continue to be tailwaters, spring creeks, and lakes. By the middle of the month, some of the freestones begin to clear and the salmonflys begin to hatch. The salmonflys are the most anticipated hatch of the year, giving anglers the chance to toss huge foam dry flys to rising trout. The Madison, Big Hole, Gallatin, Yellowstone and Rock Creek are all noted for their salmonfly emergences. On the Spring Creeks, the Pale Morning Dun hatch is the big story in June, and these Mayflys will bring even the largest fish in the creeks to the surface to feed. In Yellowstone National Park, the Firehole, Gibbon, and Madison will all fish well, especially early in the month. Look for hatches of White Miller Caddis and Pale Morning Dun’s.
July
With runoff subsiding, virtually every river in the state is fishable in July. The only exceptions would be rivers that get too warm, generally large, lower elevation rivers or those with a thermal influence (Lower Madison, Firehole, etc). July sees a smorgasbord of hatches including Caddis, Golden Stones, Yellow Sallies and Pale Morning Duns. Attractor patterns like Chubby Chernobyls, PMX’s, and Turk’s Tarantulas are good options when the trout are looking up. Freestone rivers like the Yellowstone, Gallatin, Blackfoot and Flathead are good bets for attractor action. The high mountain lakes and smaller streams really turn on in July, as water temperatures have reached optimal levels for feeding. In Yellowstone Park, the action shifts to the northeast corner with famous Cutthroat fisheries like the Lamar, Slough Creek, and Soda Butte Creek fishing very well.
August
August is terrestrial time in Montana. Insect hatches have waned, so trout key in on grasshoppers and ants that find their way into the water. Some of the larger rivers like the Bitterroot and Jefferson will become low and warm, offering poor fishing. The best fishing will be on colder rivers like the Boulder, Gallatin, Rock Creek, or Flathead. August is a great month to get off the beaten path and target lesser known, smaller rivers and streams. It’s also a great time to get into the backcountry of Glacier or Yellowstone National Park and target fish that don’t see very many flies each year. On the lakes, the famous “Gulper” hatch is in full swing in Southwestern Montana, offering opportunities for trout over 20” on a dry fly.
September
As the weather cools, fishing begins to pick back up on all the rivers around the state. Terrestrial fishing is still king, with nymphing and streamer fishing becoming important to pick up bigger fish that are starting to think about the fall spawn. Large rivers like the Madison and Missouri are good options, and the smaller streams are still fishing very well. Cloudy days in September will see good hatches of Blue Winged Olives. Around Missoula, the Bitterroot and Clark Fork see good hatches of Fall Drakes as well. September is a nice time to fish because the crowds start to dissipate. The prime tourist season is coming to an end and the locals are getting ready for hunting season, so fall is a good bet for those seeking a little more solitude.
October
As fall rolls along, it becomes a good time to swing for the fences and chase the biggest fish of the year. Large trout move out of lakes and reservoirs into the rivers and become more accessible to anglers. The Madison river is a top bet in October, both inside of Yellowstone Park and in Montana, as large trout push out of Hebgen and Ennis Lakes. Most of the fishing in October will be with nymphs and streamers, but opportunites for dry fly fishing exist. Blue Winged Olives and Fall Drakes will hatch on rivers like the Bitterroot, Clark Fork, and Yellowstone. Though you are not likely to rack up big numbers, October is a good time to chuck large streamers in search of a big Brown Trout.
November
November marks the end of the fishing season for many anglers. Early November offers the same chances for big browns as October does, with even less fishing pressure. Yellowstone National Park closes to fishing the first Sunday in November but Montana waters remain open. The weather become iffy, but on nice days the fishing can be very good. Hatches have mostly ended by now and cold water temperatures reduce the trouts desire to chase streamers, so November is mostly a nymphing game.
Winter Fishing
Winter does offer some good fishing on the right days. It is not the time to plan a fishing trip, but fishing will be productive on sunny, warm days. Top winter choices include the Bighorn, Missouri, Madison, and Livingston Spring Creeks due to the warmer water temperatures. Some freestone rivers like the Gallatin and Rock Creek can fish well, but others like the Blackfoot or Jefferson ice up badly and become unfishable.