April is one of the more exciting months of the year for Montana anglers. Although winter fishing is great...things really begin to get exciting when water temperatures begin rising in the spring. More and more water becomes accessible as ice shelves recede and snow banks melt off. One of the great attractions of fly fishing in Montana is the terrific variety that anglers can experience on the vast array of rivers, spring creeks, ponds and lakes the state has to offer. Fishing technique and aquatic hatches are also diverse and across the state and change from month to month. April is arguably the most diverse month of the fishing season in regards to fishing techniques and hatches. Spring weather in Montana is notoriously fickle and can produce both balmy warm days and blizzard like winter weather. April is a major transition month for weather with a tumultuous blend of cold winter storms and mild spring temperatures. Fishing in early April across Montana often produces winter like fishing conditions with a few exceptions. Water temperatures are still cold and trout are concentrated in slow deep runs in order to conserve energy. Prime feeding times coincide with the warmest part of the day which is generally from about noon until 4pm. The most productive fishing techniques during the early part of the month is generally nymph fishing just off of the bottom. Rainbows are spawning this time of year so be cautious about wading or fishing in the shallow riffles where trout build their nests, or redds. These will appear as lighter colored circles or ovals where the trout have cleared depressions in the gravel.
April can also offer some decent dry fly fishing in some locations. Montana fishing guides from around the state converge on the skwala stonefly that begins hatching in late March and continues into April on many of the larger rivers in Western Montana. The trout see enough of these relatively large insects to be enticed to the surface. Early April also produces some outstanding dry fly fishing over midge hatches. The best midge fishing tends to be on some of the tailwaters below dams such as the Missouri, Ruby and Bighorn. As water temperatures continue to rise the baetis mayflies (aka blue winged olives) begin hatching in earnest by the middle of April on most Montana rivers. This smaller mayfly often produces intense hatches on cloudy days that can entice nearly every trout in the river to the surface some days. Because of the smaller size of this insect trout are not quickly filled up when feeding on baeits resulting in a long and sustained feeding window. Late April produces an explosion of hatches and fish activity across the state. Midges and baetis continue to hatch but are also joined by the large march brown mayflies and prolific brachycentrus caddis (also known as the Mother’s Day hatch). Warming temperatures have also triggered trout to begin migrating out of their winter lies and they begin spreading into more traditional lies across the rivers. Streamer fishing can be very good in April and many of the largest trout of the season succumb to the massive streamers that many of our guides prefer to throw on their days off.
April kicks off some a series of prolific spring hatches. Early in the month chironomids, or midges, can produce outstanding dry fly activity in the late mornings and early afternoons. Midge hatches tend to be the most prolific on tailwater rivers such as the Missouri, Bighorn, and Madison but they can also be relevant on freestone rivers as well. When fishing over thick midge hatches try some cluster patterns vs. individual insect imitations.
Skwala stoneflies are also an important early April hatch. This smaller dark olive stonefly produces some of the first good dry fly fishing on many freestone rivers. Like other stonefly species, these insects prefer a larger rocky substrate. Western Montana rivers near Missoula, such as Rock Creek and the Bitterroot are well known for their skwala hatches but saavy anglers can also target them on rivers east of the divide as well.
Baetis mayflies, or blue winged olives, are one of the most consistent April hatches. These smaller mayflies are generally a bit bigger in the spring than their fall hatching relatives and a size 16-18 is often the best match. Baetis love to hatch under cloudy skies and some of the thickest hatches will be found on days when the snow is flying or spring rains settle in.
One of the most exciting spring hatches is the Western March Brown. March brown mayflies are larger and best imitated by a size 12 pattern. Like the baetis mayflies, they often hatch in abundance on cloudy days. Even larger trout can be enticed to the surface when March browns are on the water.
April fishing strategies
April can provide some exceptional dry fly fishing during good hatches. Generally you need to be fishing over an active hatch to find success on the surface. This is not the time of year to prospect with attractor dry flies. If you don't see bugs on the water and actively rising trout, you will be better off fishing subsurface. When fishing over the March brown and baetis hatches also make sure to try emerger patterns in the surface film. This is best achieved by fishing one traditional dry fly pattern trailed by an emerger pattern as your second fly.
Nymph fishing is very effective in the spring. This will nearly always be the best approach in the cooler mornings when fish are concentrated in deeper holding water. Fly selection doesn't need to be too complicated. Target some of the year round staples on the fishery you are on. Generally some stonefly patterns, baetis nymphs, midge larva, sow bugs for tailwaters, worm patterns and egg patterns are all you will need.
Streamer fishing can also be exceptional in April. This isn't the time to put large numbers of fish in the net stripping streamers but it can produce some real monsters. Remember that fish are still in deeper holding water or slower tail-outs. This isn't the time of year to pound the banks when streamer fishing. The best tactic is to use a sinking head and a slow retrieve.
April fisheries to target
April water temperatures are still relatively cool. The best waters to target in early spring are the larger rivers and spring creeks. Smaller mountain streams tend to produce tough fishing with the colder water temps. The larger fisheries will have stronger hatches and also more active trout. The exception to smaller waters are spring creeks which are groundwater fed and have elevated spring water temperatures and productive hatches. In late April as air temperatures climb be sure to pay attention to water levels as some rivers can begin to rise from low elevation snowmelt when high temperatures reach the upper 60s and higher. Tailwater rivers below dams are a safe bet on these warmer than average spring days.
When to fish
Time of day has a huge influence on fishing during the month of April. Early morning water temperatures are cold and fish are often lethargic early in the day. Aquatic hatches and trout both become more active as water temperatures rise and generally late morning and afternoon are the most productive times of the day. If you only have a few hours to get out the 11am-3pm window is a safe bet.
April weather and its impact on fishing
If you don't like the weather, wait 10 minutes. This statement is never more true then in the month of April! Weather is a big driver for fishing in the early spring. Pay attention to the wind forecast, cloud cover and air temperatures. April can produce wet snowy days or blue bird tee-shirt weather and everything in between. Poor weather days are not to be avoided in April and often produce exceptional hatches. If you see a steady drizzle, cloudy skies or snowy weather in the forecast expect to see strong hatches of baetis and March brown mayflies. On bright and sunny days midge hatches can be great in early April.
After a long winter it is always a pleasure to get out and enjoy warmer days and some great spring fishing. Montana tourism season hasn't kicked off yet and the rivers are quieter than they will be in the busier summer months. April is a very dynamic month with conditions and hatches changing by the hour and by the day so pay attention to weather and river flows. If you invest enough time on the water in April you are sure to encounter some excellent fishing opportunities!