Hebgen Lake Fly Fishing
Hebgen history
The Basics
Construction on Hebgen Dam began in 1910 and was completed in 1915. Once filled, Hebgen became the seventh largest man-made lake in the world. Important reminder that major dam/reservoir projects were still years out in the future. Fast forward to today and it's barely a top ten reservoir (in size) for Montana.
The Stats
Elevation: 6,535 ft.
Surface area: 12,500 acres
Length: 15 miles
Shoreline: 65 miles
The Fish
Hebgen Lake has a strong population of rainbow and brown trout. Westslope cutthroat are fairly common, and the rare grayling can be found along with mountain whitefish and Utah chub. There is no presence of bass or pike, leaving the trout population without any considerable competition.
Seasons
Spring (ice-off thru mid-June)
Hebgen Lake will typically thaw sometime in April, possibly early May if we're having an especially rough spring. Until enough ice has melted that the boat ramps are open, there are plenty of great wade fishing opportunities.
Early on and throughout the spring season, leech patterns are an excellent choice as the water starts to warm up. There can certainly be some tougher days mixed in as water temperature layers change through the lake. But, as the lake warms up a bit, you'll start to see a lot of chironomids hatching. Fish can be tough at times to trick on the dry, but emerging patterns fished below the surface can be very productive.
Summer (mid-June thru mid-September)
Mid-summer is when most of us first gained our love for fishing Hebgen. Typically you'll find callibaetis hatching en masse from mid-July through August, and possibly the first few weeks of September if the weather remains warm.
Chasing rising "gulper" fish is an experience every fly angler should have. Instead of focusing on covering a lot of water with long drifts like we do on rivers, you'll be waiting to cast until there's a rising trout within range. Lining everything up is the challenge; these dry-fly eaters are spooky and have to pick out your fly out of the thousands of natural bugs in their zone.
Fall (mid-September thru ice-on)
As the weather starts to cool down, hatches will slowly taper off, and the leech game is back in force. Many anglers will be amazed by the minimal amount of angler traffic on Hebgen during fall as many fishermen migrate inside YNP along with the fall run of brown trout moving up the Madison River. For many lake angers this is their favorite time of year.
Technique
Streamer
Streamer fishing on Hebgen is a very effective way of catching fish. Typically mid-sized leech patterns are your best bet, but there is a wide variety of options from crayfish to blobs. Similar to streamer fishing on a river, you need to constantly mix up your routine until you get into fish; don't just fish at the same depth and retrieve at the same speed because it worked yesterday. What's worked in the past is a great place to start, but every day is a new challenge.
Nymphing
While indicator nymphing on the lake is certainly effective, slow stripping or hand crawling nymphs just below the surface offers another great technique to fool Hebgen's fish. Feeling the take and setting the hook with a strip set is just that much more fun than watching a bobber go down.
Dry Fly
With the right conditions, dry fly fishing on Hebgen can offer some of the best surface fishing around. As mentioned earlier, the fish can certainly be wary and hard to reach at times. But after the first time you have an 18"+ trout slowly sip your dry fly on a glass-calm surface, you'll keep coming back.
Tackle
Lake Rods & Reels
Rod
While standard 9' 5-weight rods are still a great option for throwing dry flies on the lake, most lake anglers will also mix in a few 10' rods in weights 5-7. The extra length and power make picking up sinking lines and double leech rigs that much easier. And don't forget, these are big, strong trout that can take you 20' deep. While the Madison River creates issues with the fast current, the fish can't take you down deep like they will on Hebgen.
Reels
Reels are less of a concern as long as you have a trustworthy drag. Most lake anglers strip line to fight fish on the lake instead of getting them on the reel. As always, have a reel that matches your rod well in terms of balance.
Lake Lines
Floating Lines
While some anglers have very specific demands for their lake dry fly line, the line you feel the most comfortable casting at distance is the right choice. But be wary of super over-weighted heads as you still want a fairly delicate presentation with smaller dries.
Sinking Lines
Sinking lines are where most new lake anglers can get overwhelmed. While you can get by with your river streamer line, the newer lake-specific lines will better match your 10' 5-7 weight lake rod. To start, get yourself a good full sink intermediate line. The full sink part is important; this will help keep your rig at depth for much longer than a 12' sink tip line. You can accomplish a lot on the lake with just an intermediate line. From there, you'll naturally gravitate to what your needs are on the lake: hover, midge tips, parabolic, type 3, 5, 7 sink, etc.
Knowing how to fish a few lines well is more important than having 30 in your bag. That being said, trying new lines is half the fun. But don't feel like you have to invest in that many right away.