The government's latest analysis of wildfires at Yellowstone National Park last summer shows that about 706,000 acres burned, a considerable swath of destruction but a far smaller total than estimates widely cited when the fires were raging.

The new figures, based on satellite pictures assessed this week, indicate that about 32 percent of the 2.2 million-acre park was burned.Maps and national news reports last summer regularly showed that far more than half of the park had been hit by the fires. Those reports, in turn, fueled political heat about the National Park Service's initial decision to heed its "let it burn" policy toward most of the Yellowstone fires.

While the impact of the fires evidently was smaller than commonly assumed, the government also released Friday several thick reports suggesting that firefighting efforts were badly hampered by bureaucratic bungling, communications foul-ups and major blunders by forecasters asked to predict how the fires might spread.

The reports are the first trickle of what promises to be a flood of studies and investigations of the Yellowstone firestorm of 1988.

The secretaries of interior and agriculture are due to receive a policy study Dec. 15 on the wisdom of the "let it burn" approach. Meanwhile, several congressional investigations are under way.

Law enforcement officials in Idaho are still contemplating criminal charges against a lumberman who is believed to have started the biggest of the Yellowstone fires - the North Fork fire, which burned 385,000 acres of timber and briefly threatened the lodge and other buildings at Old Faithful geyser.

"This guy was logging July 22 in Targhee National Forest, just to the west of the park border," said Stan Tixier of the Forest Service. "He threw a cigarette in the underbrush, and that fire just took off." Under federal law, the lumberman could be held liable for all the government's cost of fighting the fire - about $8 million.

Because foresters knew quickly that it was not a natural fire, the Park Service and Forest Service tried to put out the North Fork fire from the beginning. But the reports said that officials delayed efforts to suppress most of the other fires in the first weeks.

All the fires other than the North Fork blaze were evidently caused by lightning. Lightning can start a fire even in driving rain if it hits dry tinder that is sheltered from the rain by the forest canopy.

Because fire is a natural part of the forest ecosystem, park officials initially adopted a "let it burn" stance. The reports issued Friday - prepared by Park Service and Forest Service study teams - said that decision stemmed in part from bad guesses as to how fast the fires could spread in this drought year.

The reports suggested that park officials relied too much on the park's fire history when they made their crucial early decisions. Until this year, the biggest known fire in Yellowstone had been an 1886 blaze that burned out after destroying 25,000 acres.

"Historic data and perceptions indicated that a `large fire' was around 10,000 acres," said the report on the CloverMist fire, at the park's eastern boundary. It said the park managers' "worst-case scenario" assumed a fire spreading to 40,000 acres. In fact, the CloverMist fire spread over 413,000 acres.

The report said the CloverMist fire "could have been suppressed" at minor expense in early July if park managers had mounted a major effort. But full firefighting efforts didn't start until July 21, when the fire was beyond control. The fire burned until October; $23 million was spent fighting it.

The reports detail many communications foul-ups among the Park Service, Forest Service, and military units fighting the fires. Twice in September, fire crews were held at the East Gate and not permitted to enter the park because rangers at the gate had been told to admit no one.

But Park and Forest Service officials said Friday a major problem was that the fires so quickly became historically huge.

"You don't size a church building for the Easter Sunday crowd," said Gary Cargill, the Forest Service regional director here. "Well, this was an Easter Sunday fire, and you don't maintain all the resources it would take to deal with something that happens . . . once in history."