Here it is...the first rock garden bloom that I can actually claim!
Shown here after the first below freezing night.
I have it marked as
Draba sakuraii , and from an amateur's viewpoint I'd say it's a match.
*******
There's also a bud forming on what I have marked as
Prairie Smoke (Geum triflorum) ...at least I think it might be called a bud at this point?