Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
But the body was not segmented.
It's probably a Tipulidae (Crane Fly) larva. The lower Owens is the wrong habitat for rhyacophilids (Green Sedges). The specimen sounds too big for the hydropsychids (Little Sister Sedges) that low in the system.