Here’s an experience many trout anglers can relate with: You’re fishing a nice stretch of river with a finesse presentation—a nymph, a salmon egg, or a small Panther Martin spinner—when boom! Fish on!

In pursuit of popular game species like rainbow and redband trout, Oregon anglers often hook a less desirable, forgotten species in the process: mountain whitefish. I’ve heard all the tropes. "Whities ...