Missoula, Mont. – As insects related to fly-fishing go, the skwala stonefly gets high marks for excitement, much less for reliability.
A large stonefly that appears in late March on certain rivers of the northern Rockies, the skwala is a bug shrouded in considerable mystery. It receives little mention in angling literature and is even less known to most anglers outside the area.
Ask local experts on the Bitterroot River, where the hatch launches a stampede that signals the start of dry-fly season, and the information flow necks down to a description of what this large stonefly looks like and which fly makes the best imitation.
“I assume it’s an Indian name,” said Daryl Gadbow, retired outdoor writer with the Missoulian newspaper and a fervent pursuer of trout using skwala flies.
If so, the translation well could be “big, black, ugly bug.” Slightly more than half the size of the giant pteronarcys stonefly, or salmonfly, the skwala makes an impression on early spring trout eager for a good meal.
Trouble is, the hatch is far more erratic than most, both in timing and duration. The skwala emerges by crawling to shore, then rests on rocks or vegetation until returning to lay eggs – much like other large stoneflies.
“It’s not usually a hatch that’s overwhelming in the numbers of insects you see at any given time,” Gadbow said. “But if the fish have seen a few of them, they’ll usually hit them.”
