In February 1871, five elderly Apache women arrived at Camp Grant, a sun-scorched collection of adobe buildings about fifty miles northeast of Tucson. They were looking for a son who had been taken prisoner. Lieutenant Royal Emerson Whitman, the 37-year-old commanding officer, fed them and treated them with kindness. Word spread. Within weeks, nearly 500 Aravaipa and Pinal Apaches had gathered at a refuge Whitman established along Aravaipa Creek, about five miles east of the post. Chief Eskiminzin led them. They began cutting hay for the fort's horses and harvesting barley in nearby fields. For a moment, it seemed peace might take root in the Arizona desert.

Peace was bad for business. Tucson merchants had built their livelihoods on what historians call the 'blankets for peace' economy, selling goods to the federal government for distribution to hostile tribes. With the Apaches settling peacefully at Camp Grant, that revenue stream was drying up. Some Arizonans allegedly staged mock raids on isolated settlements to bolster public support for renewed hostilities. Lieutenant Whitman sensed the danger. He urged Eskiminzin to move his people to the White Mountains near Fort Apache. The chief refused. The Aravaipa homeland was along this creek, in the shadow of these mountains. He would not leave.

On the morning of April 30, 1871, a vigilante force descended on the sleeping camp. William S. Oury and Jesus Maria Elias had assembled a coalition as diverse as it was deadly: Anglo Americans, Mexican Americans, and Tohono O'odham warriors who had been enemies of the Apache for generations. The attack came before dawn. The Apache men were away from camp, hunting. What followed was not a battle but a slaughter. When it ended, 144 Aravaipas and Pinals lay dead, nearly all of them women, children, and elderly. Almost all had been scalped. Twenty-seven children were taken captive, most of them eventually sold off, their fates unrecorded.

Lieutenant Whitman returned to find the bodies. He searched for survivors, finding only one wounded woman. He buried the dead and sent interpreters into the mountains to assure the Apache men that his soldiers had not participated in what he called the 'vile transaction.' The Eastern press called it a massacre, and the story reached Washington. President Grant informed Arizona Governor A.P.K. Safford that if the perpetrators were not prosecuted, the territory would face martial law. A grand jury indicted 100 assailants. The trial focused almost exclusively on Apache depredations. Nineteen minutes of deliberation. Not guilty.

The Camp Grant Massacre posed a problem for Arizona's narrative of itself. The attackers were not rugged Anglo pioneers subduing the wilderness, but a multi-ethnic coalition that included Mexican Americans and indigenous O'odham. This complicated the story white Americans wanted to tell about the West. So the massacre faded from memory, displaced by tales of military campaigns against Geronimo. The perpetrators preserved their version through the Society of Arizona Pioneers, which later became the Arizona Historical Society. Today, no marker stands at the massacre site. Its exact location is only generally known, somewhere south of Aravaipa Creek, about five miles upstream from where Camp Grant once stood. In 2021, descendants of those killed spoke out against a proposed copper mine at nearby Oak Flat. The silence, it seems, is finally breaking.