R. M. Patterson writes of Northwest Canada, where there is still elbow room and he agrees with a fellow wilderness lover who put it: ""I like the mountains because they're so damn clean!"" His book is based on his own journey through the Finlay country and those of other men surveyors and trappers, for traders and geologists, and mounties (the Gold Rush), spurred by such records as Haworth's On the Headwaters of the Peace River and Butler's volumes. As he surveys the Peace River Gap or Deserter's Canyon, he recalls the men who came before Warburton Pike, who ventured through the Gap by canoe in midwinter, Samuel Black the former North Wester who surveyed the river, Swannell who succeeded him. Then there was Nicholas Ignatieff, who had the dream of colonizing the country but died before he could realize it. The author holds to pre-1916 explorations other than his own and Ignatieff's, as this is the date when the outboard came to the Northwest. Mr. Patterson (Dangerous River, Trail to the Interior) had travelled similar routes before, will engage a pre-existing readership.