This one was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
In this area, the first place to catch grayling each year is also one of the least idyllic places in Alaska to fish, a spring-fed slough in downtown North Pole where many of the Chena River's grayling congregate to spawn. It runs low and clear while all the other rivers in the area are high, turbid, and still holding more icebergs than grayling. The angling pressure at popular access points looked more like the Catskills than Alaska, but I was still excited to catch my first fish in months. The grayling were abundant and eager, and I enjoyed ridiculously easy fishing on nymphs and more interesting action on dries for a couple hours before I tired of the highway buzz and the gas station scenery and headed home. Soon, water levels will drop and the real Alaska will be ready for play.