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.
Wow, I can't believe the difference in a few degrees of lattitude! I walked one of my favorite early season wild brook trout streams on Wednesday--there was more than 2 feet of compressed snow along the banks AND this stream is located very close to Great Bay (estuary) and of course, the Atlantic ocean. My favorite streams up north probably will not be fishable until early May. You are very lucky. By the way, those trout are sublimely beautiful. You found the BEST way to open a new season!