In the hymn’s narrative of Zeus’s birth and bath in Arcadia (10-41), Rhea gives birth to Zeus, provides him (and herself) a miraculous bath in the then waterless region, and arranges the infant god’s delivery to a Cretan hiding place. But before turning to Crete, the narrative concludes with a positive focus on humankind; the very river that served as bath for Zeus and Rhea now provides water to contemporary Arcadians, described allusively in the account’s closing line in terms of their ancestral mother, Callisto: “the grandchildren of Lycaon’s daughter, the bear” (υἱωνοὶ . . . Λυκαονίης ἄρκτοιο, 41).1 This essay proposes that Callisto is in fact present in the background throughout the hymn’s Arcadian account, and that the mythical traditions surrounding her serve as vehicle for the hymn’s narrative tension and its unique construction of Zeus. Through subtle allusions across this birth narrative, the hymnist first sets Callisto in tension with Zeus’s own mother Rhea, suggesting that Rhea’s birth to Zeus on Mt. Lycaeus (10-14), and then the bath she produces there (15-32), depict a locus suited to accounts of the pregnant Callisto’s future death. With the narrative’s final lines (37-41), however, the hymnist ultimately resolves this tension, against other traditions, insisting on a Zeus who saw to the rescue of Callisto’s unborn child Arcas, and implying a Zeus who granted Callisto herself an eternal place among the stars.