‘Irreconcilable Differences’ : A GOOD YEAR TO DIE: The Story of the Great Sioux War,<i> By Charles M. Robinson III (Random House; $27.50; 448 pp.)</i>

Thirty-six years of conflict between the United States and the Sioux began in 1854 with the death of a Mormon’s cow. It reached a pinnacle of fury in 1876, when Gen. George Armstrong Custer and his troops were were destroyed at the Little Bighorn, and concluded in 1890, when the government turned Hotchkiss guns--revolving canons--on a band of nearly frozen Sioux camped beside Wounded Knee Creek.

“A Good Year to Die” focuses on 1876, summarizing the prelude and aftermath--a record of mutual intolerance, rage, fear, deceit, good intentions and perfectly human blundering. Charles Robinson has done his homework as well as the field work; he has read quite a lot and has visited many of the sites.

Scholars love to argue over trivia, and almost everything associated with the Custer debacle, no matter how remote, excites them. For instance, the wretched cow. Robinson says it wandered into a Native American camp, where it was devoured. Another historian thinks it was killed for its hide. Another claims the animal was a worn-out ox. Another believes a Native American decided to shoot a Mormon and hit the beast by mistake.

Whatever the facts, a stupid Army lieutenant named John L. Grattan tried to arrest the Native American. Thirty soldiers were killed in the resulting fight, which came to be known as the Grattan Massacre, and Washington retaliated. The scenario is familiar, but what made this incident unusual was the presence of an adolescent Sioux named Curly who would later become famous as Crazy Horse. Scholars agree that this first encounter with U.S. troops had a profound effect on the boy.

Although Grattan lay dead, his folly lived. Sioux began to attack emigrants along the Oregon Trail. Washington dispatched Brig. Gen. William Harney to bring peace. Harney attacked a camp of Brules, killed 136 and ordered the survivors to behave.

Robinson briefly recounts the next mistake on the road to the Little Bighorn, the 1866 Fetterman Massacre. Once again we meet a reckless, foolish officer: Capt. William J. Fetterman led 80 men into a Sioux ambush. One of the decoys was Crazy Horse. And the reader, knowing what will happen in 1876, begins to feel a sense of dismay.

The inexorable march proceeded, Robinson contends, because the antagonists could not understand each other. He points out that until a few decades ago, white Americans represented progress and civilization while Native Americans were seen as bloodthirsty savages. Recently, however, we have witnessed a sea change: Whites have become despoilers of the land while Native Americans have acquired the stature of virtuous custodians. “In reality, neither side was essentially good nor essentially evil. More than anything else they were different. As national development threw white and Indian into ever-increasing contact, the differences became more apparent until they were irreconcilable.”

Other historians digging toward the roots of the problem might dispute or qualify that. No matter how 19th century history should be interpreted, the ugly conflict gathered momentum. Along came the 1874 Black Hills expedition, which infuriated the Sioux more than anything the government had done previously.

Several years earlier the U.S. had agreed to prevent whites from settling, occupying or passing through these sacred hills with the Ft. Laramie Treaty. But here came Custer at the head of a clanking, jingling, noxious column of bluecoats accompanied by a 16-piece brass band. He had been instructed to reconnoiter the Black Hills in case Washington decided to build a fort, or forts. On the side, he was investigating rumors of gold. As for the treaty, a year later President Grant notified army headquarters: “Efforts are now being made to arrange for the extinguishment of the Indian title. . . .”

Gen. Nelson Miles would write to his wife not long before the Wounded Knee atrocity--or misunderstanding, as some insist--that the Native Americans had been half-fed or half-starved and could not be assured of anything different in the future: “They say, and very justly, that they are tired of broken promises.”

Robinson details the manipulation and subsequent escalation of violence by excerpting from letters, government reports, diaries, memories and interviews. His tone is unbiased, which is a difficult job for anyone trying to explain the terrible pageant. He includes quite a bit of military maneuvering: “Capt. Frederick van Vliet of Company C, Third Cavalry, was ordered to take and hold the ridge south of the river overlooking the right bank,” etc. As a result, the narrative sometimes becomes diagnostic; but historians must depend upon mundane facts to reconstruct events.

June 25, 1876. How often has it been discussed, argued, filmed, painted, described? Sitting Bull, Custer, Gall, Reno, Wooden Leg, Benteen, Crazy Horse--they will never die. Without doubt, the Little Bighorn strikes at something embedded in the American psyche.

Amateur scholars as well as professionals look eagerly for reasons to criticize a new book on the Indian Wars. Here we have Irish adventurer Myles Keogh’s famous horse, Comanche: “officially the only survivor. . . .” Officially, yes. True enough. However, that phrase encourages the myth. In fact, dozens of Seventh Cavalry mounts survived, perhaps 100, along with a yellow bulldog that followed the regiment from Ft. Lincoln. Robinson does note, 119 pages later, that several horses with Seventh Cavalry brands were recovered after the Lame Deer fight--even so, peevish historians may jump on his back.

The most debatable question is this: Why did Custer lose? Robinson blames it on happenstance, an unpredictable day when things went wrong: “Where the established military system simply broke down, where the Indians took extraordinary measures to defend their homes and families; where an entire battalion, terrified beyond the limits of endurance, fell apart.”

In certain camps this interpretation will be furiously denounced, but Robinson is entitled to his moment. “A Good Year to Die” has been solidly researched and is clearly presented, a book of permanent value to Western history fanatics.