"The Big Sky" is an authentic and exciting novel about the mountain men and their lonely country. Mr. Guthrie … has poured into his book all of the Westerner's fierce fondness for sun and sky and space, and he has succeeded in explaining (perhaps for the first time in fiction) what motivated the wildnerness wanderers of a century ago, the rough and ruthless men who dreamed of freedom under the big sky….

[Men like Guthrie's hero Boone Caldwell] do not lend themselves easily to the novelist's manipulation, and one may wish occasionally for fuller exploration of his character; but the character is consistently drawn, and he is convincing as representative of the inarticulate, courageous, often ruffianly company of which he was a member….

Parts of "The Big Sky" are brutal; this is no adventure book for boys. There are memorable pictures of the back-breaking struggle to haul a keel-boat...