Leonard Wibberley
Attar of the Ice Valley
1968
from the dust jacket:

Attar is a story of our Neanderthal ancestors, who lived in the world's ice ages and managed to subsist, hunt, and raise their children in territory as climatically terrible as modern Greenland. It tells the story of one small tribe who, under the leadership of their wisest man, Old Huru, and Attar, a young hunter of more than average intelligence, at last makes it away from the hunted-out ice valley to a more promising land. Before this happens, Attar proves himself in a fight-to-the-death with Black Ear the dungo (wolf), goes down into the cavern of the Great Bear who rules all things, dares the spirits of the ice heights, and along with Huru and his sister braves the water-that-never-freezes to lead the tribe to safety.

Mr. Wibberley says of Attar: " I wrote this book out of sheer admiration for Neanderthal man. He had enormous courage, for he killed animals far bigger than himself with fire-sharpened wooden spears and a few limited stone weapons. He tackled the great cave bears, which stood seven or eight feet to his five, with a spear, and with the same spear he killed woolly rhinoceros and mammoth, wild horse and deer and wolf. He survived the world's ice ages by learning to make fire and probably erect (when a cave was not handy) a windproof temporary shelter.

"His nature was by no means animal. He buried his dead with care and pity, and he had religious feelings, for he stacked the bones of the cave bear in symbolic patterns in a Swiss cave high among the ice fields. He made little statues of clay or soft stone which are thought to be fertility goddesses, so he was concerned with the questions that lie at the bottom of all religion: Why am I here? Who am I? Where am I going?"

A gripping re-creation of life lived on the hardest imaginable terms, Attar's story illuminates man's prehistoric past in a masterly narrative which at the same time is as correct culturally and anthropologically as modern studies can make it.