The Nanabozho narratives belong to the aadizookaanan, the sacred stories, and those are told only when there is snow on the ground. The rule is stated plainly in Anishinaabe communities and is widely observed, and outsiders regularly mistake it for a quaint seasonal custom, like a song sung at a particular festival.
It is not that. The aadizookaanan are spoken of as beings in their own right rather than as tales about beings, and telling one calls it into the room. The season restriction is about when it is appropriate to do that, and the reasons given include that other beings are listening in summer who are not listening in winter, and that a story told out of season imposes on the teller and the told. A person who breaks the rule is not committing a faux pas; they are doing something with consequences.
That has a direct effect on what a reference work can responsibly do. The atlas describes who Nanabozho is, what kind of figure he is, and what the cycle does, and does not set out the narratives themselves in a form intended to be read aloud on demand in July. Printed collections of the stories exist, many of them made in good faith and some by Anishinaabe writers, and a reader who wants the narratives should go to those and, better, to a community.
Nanabozho is not archived. He is a living figure of a living tradition, and the appropriate posture toward the material is a guest's.