As part of a recent trip to Montana (much more detailed report to come when I have time), I was fishing a very high lake (around 9500 ft) with golden trout high in the Beartooths. In the evening, a pod of probably 20-30 trout, some of them pretty large, were feeding up and down a small ~30-yard section of shore near one of the little inlets. Whenever the wind died down, they were rising very frequently, with mostly bubble-less riseforms that looked like they were sipping emergers slightly below the surface.
The only bugs I could see on the water or in the air were extremely tiny pale-yellow-bodied midges, around size 26 or so, in pretty good numbers. My dry fly did once hook the exuvium of a larger midge pupa around size 16. I didn't see any other sign of those, but I had to wonder how many there must be for me to accidentally hook one on a dry fly.
I think the fish were taking the tiny things, but that exuvium casts a little bit of doubt. I didn't come well-prepared for tiny midges at all, so I was throwing all manner of miscellaneous small flies at them, including dries, emergers, and nymphs, mostly imitating tiny mayflies or caddis, and I downsized to 6X and eventually 7X tippet just to take that variable out of the equation. (That backfired when I finally got a take from a heavier fish and snapped the 7X.) I ended up only catching one naive 9-incher during the start of the activity, and missing strikes or brief hookups from a couple others. But there were dozens of rejections or rises within a foot of my fly while ignoring it altogether. It was one of my most spectacular failures of hatch-matching; I don't know if I've ever shown more flies to more fish with fewer strikes.
I might have caught another one or two that evening if I'd continued to flog the water until dark, but my wife was getting cold, and there was a bear. She was not keen on going back to the tent to warm up by herself.
Golden trout continue to impress me with their elusiveness. I had more luck the next day on small fish, but this failure really sticks with me and leaves me wondering what I should have done differently. I've never read about ridiculously tiny flies being a requirement on high lakes, but that seemed to be the case here. Does anyone with more experience there have any insights?
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist