To start with, this book is a tragic story of the Inland Inuit of Northern Canada in the mid/late-1940s. Mowat ventures North to escape the horrors of WW2, and ends up meeting the fascinating people known as the Ilhamiut, or People of the Deer. Mowat then proceeds to tell a hauntingly beautiful story of how these people were set up to become dependent on white men (trading their spears and deer for guns and fox pelts) only to be screwed when the money went (literally) south and they were left with neither the tools (ammunition) or knowledge (traditional deer hunting techniques) that they needed to fight off hunger and its attendant companion, disease. He returns a second year, and learns their language before going off on a long canoe trip to help a biologist peer find the caribou herds that are no longer around the Ilhamiut. At the end of the book, as well as throughout it, Mowat is scathing in his reproach of the white men who took callous, or deliberate, advantage of the Inuit, as well as the government that failed to do anything of significance to help them. This book did tremendous service in bringing the plight of the Inuit, and of Northern Aboriginals in general, to light for the general Canadian public.
In this light, it's a fantastic book. The stories are fascinating, the people are compelling, and the scenery is awesome. I quite enjoyed reading it. There's just one problem keeping it from getting a full five stars: it might not be 100% accurate.
Yes, much has been raised about a 1996 criticism of the book by John Goddard. But I place less stock in that report than from an actual peer-reviewed anthropological journal, Man (1955, pg. 108-109) that published a formal review of the book that questioned a few key facts in the book. First, Mowat didn't go up by himself, nor did he go on a whim, he was part of a large, organized expedition to study the Canadian North. Second, the reviewer rightly questions Mowat's ability to learn the complex Inuit language in a single month. Learn it well enough to be able to understand and relate the haunting, complex stories presented in the book. Maybe Mowat is a linguistic savant, but this certainly doesn't seem like a lot of time to learn a completely foreign language. Third, Mowat didn't really spent that much time with the Inuit (two summers), so some of his sweeping claims about their history should be taken with a grain of salt. I should note that much of what he says about the Inuit's moral and social behavior does fit very well with what has been published by respected anthropologists (e.g., Jean Briggs).
Mowat has reportedly responded to these claims (and those about Never Cry Wolf) saying, in general, that he holds big truths as more important than little truths. In that regard, there's no doubting that his book captures the essence of the beauty of the Canadian arctic and (some of) its native people, and that it captured the general apathy and/or incompetence of the Canadian government in helping a group of people clearly in need and under their responsibility.
So as long as you read this book with the general caveat in mind that this book is more about themes than details, that it's not a serious anthropological body of work, it's a fabulous read. The fact that such a caveat is not placed in the book, particularly at this late publishing date, is why it gets four stars instead of five from me.