What makes a massacre site holy? What makes it moving?

These are some questions I've been asking myself on a late-summer road trip in the West.

The questions take on meaning as we approach another anniversary of 9-11, this one marked by the controversy over the so-called Ground Zero mosque.

Is Ground Zero "holy," "hallowed" or "sacred ground"? Are other American massacre sites? What does "holy" mean in a secular society?

America is not like Europe, with many sites and relics devoted to martyred saints. But not a few of our national shrines are devoted to mass death.

A few years ago I wrote about how America's national park system paid tribute to ecological disaster. The Grand Canyon, Bryce, Yellowstone, The Badlands, Petrified Forest, Mt. Rainier: all are monuments to eruptions, erosion, earthquakes, floods, climate shifts, and extinctions. In short, we like to vacation at sites that embody the destructive force of Nature.

Many of our national historic sites are also dedicated to the kind of disasters we humans bring upon ourselves. For example, I have stopped to ponder the graves of the missionaries Marcus and Narcissa Whitman near Walla Walla, Washington where they, and many of the men, women and children with them, were slaughtered, scalped, mutilated, and decapitated by Cayuse Indians who believed these do-gooders were spreading disease, not curing it. The Whitmans were key pioneers along the Oregon Trail, and have been called the "first Protestant martyrs" in the far West, for those keeping track. You can pay homage to them alongside a surviving slice of the trail.

You can also stop by the roadside and see the prairie where Utah's Mountain Meadow Massacre took place. This is where Mormons disguised as Indians attacked an innocent wagon train passing through. Resisted, the attackers shed their costumes and offered to "help" the passing settlers, then killed almost all of them (a few children survived). A look at the skulls of victims revealed multiple gunshot wounds.

Scholars still debate whether the slaughter was ordered by church leader Brigham Young. Still, in light of the controversy over the building of an Islamic community center near Ground Zero, some have pointed out the irony that at the hallowed ground of Mountain Meadows, it is the Mormons who control the memorial.

Or you can stop by the "battlefield" at Wounded Knee, the site of the 1890 winter massacre of Sioux by the U.S. military, which even the park service website describes as a "regrettable and tragic clash of arms." Here, on South Dakota's Pine Ridge Reservation, scores of Indian men, women, and children were mowed down by Hotchkiss guns, a light-weight cannon used by the cavalry. This was a massacre of the Sioux to avenge another massacre that occurred in 1876.

The Little Big Horn battlefield in Montana is hardly a place where innocents were slaughtered. Gen. George Custer and his men were soldiers who faced Sioux and Cheyenne warriors in battle, and were virtually wiped out, though some non-combatants died as well. The defeat was a shock, with not a few echoes of 9-11. As a Park Service ranger pointed out recently, when news reached the American public celebrating the July 4th centennial of American progress at the Philadelphia Exposition in 1876, the country was shocked that their civilization had been successfully attacked by "uncivilized" guerilla warriors. As Alexander Graham Bell unveiled his new telephone to the public, the nation's finest cavalrymen were killed by guys with bows and arrows. No one expected Custer to be defeated any more than we expected the World Trade towers to fall.

The more one learns about the battle, however, the more inevitable the disaster seems. Custer, no innocent at civilian killing, having raped and pillaged Indians in encounters like the "battle" of the Washita, was at war under the nation's flag and regimental guidon. He made bad decisions at the Little Big Horn, overestimated his own abilities, and underestimated those of his enemy. The Indians were not so primitive as they were reported to be. It turns out that they might have actually outgunned Custer's command with repeating rifles that had more fire power than the government-issued carbines with which Custer and his men were defending progress. For his part, Custer declined taking newfangled Gatling guns into battle for fear they would slow him down.

The Little Big Horn National Monument is easy to get to, not far off I-90. It is a strangely compelling place with its beautiful hills rolling into the distance, and the green valley where the Indians encamped, marked by trees that line the Little Bighorn River. I first visited here in 1969 when the hilariously revisionist western Little Big Man was being filmed down the road. We witnessed an Indian charge that gave us an odd sense of displacement in time and made it easy to imagine Custer's men, outnumbered and overwhelmed in a landscape that is at once both a living grassland and a desolate place. It is made more so by the lonely white markers that dot the hills at the spots where the bodies of Custer and his butchered men were found. More than 260 soldiers, scouts, and civilians (including a reporter) died that day.

It is one of only three battlefields in the world, and the only one in the Western Hemisphere, that marks the spot where each man fell. There is no symmetry of the veteran's cemetery here (except in an adjacent military grave yard that contains vets from the Indian wars through Korea). The white stones hint at the chaos of battle, of men cut down in ones, twos and threes or in small isolated groups, many trying to escape, some shooting themselves to avoid capture, most mutilated horribly after death. Many of the troopers were immigrants who barely spoke English, some cavalrymen who could hardly ride their tired, undernourished horses, others having little training in the hand-to-hand fighting that it came down to at the end.

The Little Big Horn has power as a monument to folly, and as a shrine to the chaos of battle. The victors, like Sitting Bull, look bigger in retrospect, and more sympathetic. The loser, Custer, seems small, vain, and foolish. The men who put their trust in Custer seem especially unlucky. Some 5,000 books, it is estimated, have been written about Custer and the battle, but the fog of war lingers: Why did it happen, and how? Who was to blame? Is it a battle to celebrate (certainly some Indians regard it as a rare triumph) or a monument to hubris? It's hard to read about Custer and not think that karmic justice was doled out at the Little Big Horn.

Standing on those hills, following the trail of the dead down toward the river, reading their names, reading about the bones and bullets that have taught archaeologists so much about what happened, is to experience a tableaux of vanity, a lesson in the dangers of over-reach, of what happens when an individual, a nation, a civilization, abandons humility. Even as is is easy now to revile Custer for much of what he did, it is hard to escape the fact that we are also the inheritors of the world he helped to make with horse, sword, and ego.