Steve Galleta has been updating his Bighorn River Fishing reports blog which is a spinoff of his Bighorn river fly fishing guide site, Montana Trout Anglers. Steve operates on the Bighorn river out of Fort Smith.
The following guest post and images are by Dave Palmer, Steve’s lead Bighorn River Guide.
Midge Matters on Montana’s Bighorn River
In Gary LaFontaine’s book, “Fly Fishing the Mountain Lakes”, he states that a gram of scuds has 3880 calories while a gram of midges is worth 5280 calories. Given that there are quite possibly billions of midges in a relatively short stretch of the Bighorn River, you can see why midges matter.
Midges live an all types of water but are especially abundant (and important) in tail waters like the Bighorn. They are also important because they are available year round and are a mainstay meal for trout during the winter when other insects aren’t available. During the rest of the year they supplement other food types as they become more available.
Winter and spring are probably the best times for offering midge imitations. Larva, pupa and adults are around every day and as the days get nicer in early spring, the hatches become thicker. Dry fly midges in the winter? Absolutely. Last February a friend and I cast midge imitations to dozens of rising fish with the air temperature being a brisk ten degrees. All it took was a little bit of sunshine to get the midges, and subsequently the fish, active.
Midge meal from the Bighorn River
As larva, midges come in many colors. Olive, black, brown, tan, red and cream are common on the Bighorn river. The colors vary with the season and water type.The sizes are typically small, from size 18 down to miniscule, but occasionally one comes across some that are as big as a size 16. Larva live in the river bottom but are in the drift often and I find them in most stomach samples.
Stomach pump from the Bighorn River, Montana
Pupa, the next step in a midge’s life, are as diverse as the larva. Black, olive, tan and root beer are common colors on the Bighorn and vary in size from 16 to 22, with 18′s and 20′s being the most commonly fished. The pupa are often highly segmented whereas the larva are typically more uniform in color. As the pupa emerges into the adult, this is where it really gets interesting. Fish can key in on the rising pupa because they are easy (and very abundant) meals. The pupa get trapped just under the surface which creates a great opportunity for hungry fish to feed.
Fish keying in on pupa can be quite frustrating. An angler will often see the dorsal and tail fin breaking the surface. The urge is to put on a dry fly but fish focused on pupa pay little attention to surface flies. A short dropper off a dry can be very effective as well as a very light nymph rig. Swinging emerging style nymphs downstream to these fish can be very effective also.
Adult midges are similar to the larva and pupa in that they come in two sizes, small and smaller. Size 18-20 patterns are effective, but in the spring, there are midges that get as big as size 16. Once you see noses breaking the surface, the fish are usually willing to look at surface flies. The more common adult midges come in variations of olive, grey, cream, and dark grey (nearly black). Flies that imitate emergers and cripples with some part of the fly being below the surface are very effective during the hatch. A long, light leader is essential so small flies aren’t floating unnaturally. The smallest and often unnoticeable drag will get consistently refused.
The real fun begins when the mating clusters begin to build on the water. Some days, the surface looks like gray fuzz. This mass of mating midges really brings the fish up and they can be pretty indiscriminate since they are just sucking in mouthfuls of midges every time. Perfect presentation isn’t as important because so many midges are skittering on the surface and skating a fly a little bit can grab the attention of a greedy fish. Griffiths gnats and Adams in size 16 and 18 are very effective when fish are gorging on the mating midges. Anything that mimics a lot of midges dancing close together will do the trick.
The midge hatch usually presents the angler with two hatches each day, one around mid-day and another in late afternoon. Early, warm days can get midges going as early as 10 am, sometimes earlier but more likely closer to lunch time. The second hatch generally gets going between three and four pm and can last into darkness, late winter and early spring, that’s still fairly early.
While late winter and early spring don’t seem like ideal fishing times (and sometimes they aren’t), fly fishing on the Bighorn river, thanks to midges, can be outstanding with both nymphs and dry flies.
