Actually, A River Runs Though It was not his first book. In 1943 he co-wrote A Manual of Instruction in Military Maps and Aerial Photographs. This tells us quite a lot about the kind of writer he was: it is easy to imagine him poring over charts with compasses and a slide rule, pacing out the ground to check that the trees really did spread across the gully as marked on the map. Maclean was a rare thing: an exact, patient man who went to a lot of trouble to make sure he knew what he was talking about. 'As for me,' he writes of the forest rangers in this new work, 'I am not as important to them as the fuel moisture content for that afternoon.'
Young Men and Fire was the major preoccupation of Maclean's last years, and it is an astonishing story. In 1949 a blaze scorched up a mountain valley near the head of the Missouri river. Fifteen firefighters - a crack unit known as the Smokejumpers - dropped in by parachute to get it under control, but were outwitted by the flames and had to run for their lives. As Maclean puts it in a sombre aside: when it comes to racing with death, all men are not created equal. Only three escaped. The rest were incinerated, some of them just a few yards from the rocky ridge they were bursting their lungs to gain.
The almost-complete manuscript was praised to the skies in America when it was published in 1992, and quite right too. It is, almost literally, brilliant: a very gripping narration of what happened and a profound reflection on what it all means.
Maclean is no Tom Wolfe: he goes for a quieter sort of poetry. But his description of the Smokejumpers - glamorous, hearty, all- night types - can't but remind us of the ball- of-fire pilots in The Right Stuff. They were backwoods daredevils: young, strong and sure of themselves. They had, as it were, the bright stuff. But Maclean's book is tinged with fateful hindsight. 'In 1949 the Smokejumpers were still so young that they referred affectionately to all fires they jumped on as '10 o'clock fires', as if they already had them under control before they jumped. They were still so young they hadn't yet learned to count the odds and to sense they might owe the universe a tragedy.'
The tragedy, when it came, was full of strange inflections. The team dropped in at the top of a steep-sided valley called Mann Gulch. The fire was on the south side, quite high up. The Smokejumpers packed their digging tools and headed for the base of the fire, where they would cut a wide trench and contain the flames on the crest of the hill. But the fire jumped across the valley and started heading up towards them. It was a hot August day - the hottest on record - and the woods and grasses were ready to explode. Bizarre wind patterns swirled the fire into a storm. Soon it was moving at 100 yards a minute, with flames maybe 30 feet tall. The men didn't know any of this, but at a certain point they realised they were in trouble, dumped their tools and fled.
They made for the ridge - a stony reef at the top of a slope so steep you have to hang on with your hands. And then an extraordinary thing happened. The foreman, an unbelievably composed man called Dodge, lit his own fire. He estimated, he said later, that they had only 30 seconds - not enough time to make it through the rocks. So he knelt in the waist-high grass, fumbled with his gofer matches and started a new fire just ahead of the advancing inferno. There is a standard procedure which involves fighting fire with fire, but Dodge had something else in mind - and he thought with his hands. He beckoned to his crew, but they ignored him and ran for it. 'To hell with that,' one of them said. 'I'm getting out of here.'
Two of the Smokejumpers - the youngest and fastest - squeezed through a narrow crevice and tumbled down a rock slope on the other side. A third, only seconds behind them, fell just short. The rest were picked off in a ghoulish photo-finish. Little crosses mark the spots where they fell. Dodge, meanwhile, soaked his handkerchief in water and lay face down in the ashes of his own fire. He was in the heart of what they call a blowout, a terrifying combination of superheated gases and fresh fuel. Mann Gulch erupted. Ten minutes later Dodge stood up, uninjured. In the heat of half a moment he had invented an inspired new tactic.
Or had he? Rangers swarmed up and down the slope, measuring the path the men took, trying to figure out exactly what happened. And slowly the idea emerged that the crew had been killed not by the main fire, but by the one Dodge had ignited to save himself.
The truth is not clear even now, though Maclean is inclined to exonerate Dodge. He has earned the right, for he did not just parachute in on this story; he got on his hands and knees and dug it out for himself. An old man in his eighties, he went back to Mann Gulch and climbed the sheer slopes, counting out the yards, counting off the minutes, pondering the lie of the tree stumps. He pauses often, like an old man catching his breath, to brood on the nature of stories, the force of tragedy in our lives and the equivocal nature of history. He notices a wave going the wrong way on the river, and unravels the unusual wind structure around Mann Gulch. He takes the two survivors back to the rock slope and pinpoints their position by finding a can of potatoes with two punctures in the lid. He studies photographs and calculates bearings, and proves that a key point - the place where Dodge lit his fire - has been inaccurately recorded.
It is a masterpiece of faithful, compassionate research, and there is no false doom. The men do not hurry along the gulch knowing what is about to happen. They look down at the fire and find it 'interesting'. Only at the last moment do we lose sight of them, as the smoke swirls in and blots their lives, and our view of their death. Maclean's prose is unhurried and philosophical, yet the book burns your fingertips. At one point the men turn to look at the fire which will kill them very soon, and find it spectacular. 'Of the stations of the cross they were to pass,' he writes, 'this was the aesthetic one. On forest fires there are moments almost solely for beauty. Such moments are of short duration.' We are fortunate indeed that Maclean's life was long enough to let him explore them for us.