Both foraging in the SE corner of Lake 13. Petite mostly white terns, with black crowns and deeply forked, white tails. Bills thin and red (one bird's bill was slightly more orange) with dusky tip. Dusky primaries formed a clear triangle on one individual. The other showed less dusky, but it was not the thin edge I would expect for an Arctic (this bird's dark coloration in the primaries was much more extensive). Powder gray underparts and upperparts. Head white (aside for the crown). Silent.