Meredith Ann Pierce
The Woman Who Loved Reindeer
1985
When her sister-in-law brings her a strange golden baby to care for, a young girl, living in the cold lands far to the north, is unaware that this unusual child will help her fulfill her destiny as leader of her people.

In a wintery land where two moons shine, a young girl named Caribou falls in love with a man who isn't a man at all...

When the seasons change he becomes a reindeer and leaves, breaking her heart. Part mortal man, part golden stag, he is a shapechanger who cannot remain in the human world for long.

But when fires and earthquakes ravage Caribou's land, threatening the survival of her people, Reindeer returns. Though untrustworthy and wild, Reindeer alone knows the way out, and Caribou and her people must rely on him to lead them across otherworldly realms, past the horrors of the trollwoman's hedge, into the hall of the Firekings, and beyond — to a place they hope to call home.