Backes (Canoe Country: An Embattled Wilderness, not reviewed) knits together a yeomanly portrait of Olson, a force in the mid-20th-century environmental movement, but someone today's readers may find a bit of a dinosaur. Olson will best be remembered for authoring such conservationist hymnals as The Singing Wilderness and Reflections from the North Country, where he vented his land aesthetics and spiritual beliefs. His ego was such that, after reading Thoreau, he felt ""no one has as yet developed a philosophy of the wilderness. That is up to me."" And it is to the credit of Backes--an unabashed Olson fan who treats his papers and diaries as if they were sacred relics--that he includes such nuggets. The son of a strong-willed Swedish Baptist minister, Olson evolved a kind of wilderness theology--a love of all life in God's cosmic adventure--that found ""ritualistic significance"" in the uncivilized world. These days, Olson's writing feels by turns overly manly (""My work must be strong and hard and masculine"") and overly sentimental; readers may well agree with the Houghton Mifflin editor who rejected Olson's first collection: ""Essays . . . have to be superbly written to have a chance, and Sig Olson's prose is not on that level."" Thus Backes wisely devotes significant space to Olson's championing such then-crazy notions as roadless areas and air reservations (patches over which no flights are allowed) and to making sense of a man who bridled at the thought of being behind a desk, who would rather have been in a canoe, yet accepted numerous administrative posts, from college dean to president of the Wilderness Society, with many a bureaucratic stop between, hating them all the while. Impeccably researched, near-claustrophobically detailed, evenhanded--Backes's volume gives a sense of the Olson behind the legend.