Lakes Report - May 30, 2024
As spring slowly warms into summer here in the Headwaters, both aquatic vegetation growth and stillwater insect activity begin to kick into a higher gear. Water temps are rising out of the basement and the metabolic rates of trout (and their overall spunkiness) it following the same trend. Sluggish ice out tug of wars are now replaced by blistering runs and thrilling leaps. It's a great time to be on the stillwater.
On Hebgen, the chironomids are the overwhelmingly predominant insect right now, and the pupae of the emerging insect are the number 1 menu item. That would seemingly make fly selection very simple, but it is not often the case. Chironomids include a huge number of species that range in size from soooo small to almost an inch long. On Hebgen, however they range primarily from size 16 or 18 to 10 or 12 depending on your hook style choice, and bodies are typically dark shades of black, brown, and olive. The other challenge associated with matching chironomid pupae is knowing when a hatch is happening, and then dialing in your presentation depth. In warm, calm conditions the trout may be feeding on the emergence right in or just below the surface film. You'll know it's happening for sure. It is them that you'll see riseforms, and can target the first "Gulpers" of the season. Your pupa imitation will need to either float or suspend just below the surface. But, often an emergence will occur during choppy conditions or the fish may simply be feeding deeper in the water column do to ambient light or some other factor. With no surface feeding activity, how do you know that a hatch is on? Get your face down near the water's surface and look for those shucks left behind by emerged chironomids. If you are lucky, you may even see some pupae wriggling there near the surface. Note the size and the color if you can. Start there with your fly choice and then start experimenting with presentation depth. A two fly rig can be a huge help here. My typical rule of thumb is to space my two flies out about two feet apart in water 6ft deep or less, and then space the flies out more and more as I fish deeper water. The goal is to try and cover the widest range of the water column effectively. Remember, you can only fish two flies here in MT, compared to many places where 3 fly rigs are common stillwater rigs. Don't get discouraged if it takes a couple of depth changes to dial it in, and definitely don't get complacent with a set it and forget it mentality.
If you are out on the water and NOT seeing chironomid shucks, you can still give them a try as trout often recognize them as a tasty snack. Alternatively, break out the buggers and sink lines as many trout at this time of year are hunting for meaty food items like leeches, small baitfish, and crayfish!
One final reminder: We use Hebgen as a baseline for our stillwater reports simply because it is so close to the shop. But there are lots of stillwater fisheries in our area. The main thing to consider on the other lakes and ponds is their elevation and depth characteristics. Higher elevation lakes or lakes that hold a lot of deep water will be well behind in the annual bug and fish activity cycles, while lower elevation and/or shallower water bodies will often be well ahead!
Take care and Fish on!
