The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
I collected this larva and several like it from the same stream and on the same day as this pupa. I suspect they're the same species.
This caddisfly was collected from the Long Lake Branch of the White River in Wisconsin on June 5th, 2005 and added to Troutnut.com by Troutnut on May 25th, 2006.