Someone on iNaturalist suggests this may be something called Firedots – Genus Caloplaca.
Caloplaca is a lichen genus,[1] composed of a number of distinct species. Members of the genus are commonly called firedot lichen,[2]:235jewel lichen.[2]:235gold lichens, “orange lichens“,[3][4] but they are not always orange, as in the case of C. albovariegata.
It has a world-wide range, so no surprise finding it at Split Rock.