It's always interesting to me to think of how history could've been different, and the We Shall Remain series has provided a lot of fodder for this.
Geronimo's story happened much too late to stem the tide of US history. But it's possible he and the Chiricahuas could've preserved most or all of their Apacheria homeland. Let's see how it could've happened.
In 1884 only one thing stood in the way of United States expansion: the Apaches. The U.S. Army believed it could easily defeat this ragtag band of savages who viewed one another more as rivals than allies. But one of those "savages" was a military genius: Juh, "He Who Sees Ahead." It was Juh's vision that persuaded the various tribal leaders to set aside their differences and work together, thus turning the disconnected bands of warring Apaches into the most cohesive fighting force the West had ever seen--and crushing the invading army.
Thus was born Apacheria--the Apache Nation--and a world where Juh and his son, Little Spring, matched wits and weapons with a cast ranging from Teddy Roosevelt and Carrie Nation to Al Capone and J. Edgar Hoover. A world where it was best to stand with the Apaches, and never against them....
In reality, Juh died just before the events of this novel. I don't know if he had the "vision thing" or could've united the disparate bands. But the Apacheria scenario itself is plausible. If not Juh, someone could've done it. Perhaps another Apache leader whose life was cut short.
Dreaming away the whites
A website describes Nochaydelklinne's effect on the Apaches:
The Apaches were not one tribe as in other cultures. They were independent bands, and some of them were bitter enemies. The government refused to recognize this distinction, and when it forced a number of bands from Arizona and New Mexico together onto the San Carlos Reservation, it was only a matter of time before hostilities erupted. As the Apache watched in growing desperation, they became crowded with their enemies, whites overran their lands, and dishonest agents sold their rations, forcing them to go hungry. Apaches everywhere accepted the promises of Nochaydelklinne.
By 1881, Nochaydelklinne was a full-fledged prophet attracting larger and larger crowds. ... Already, Apaches who had previously been mortal enemies were beginning to fraternize. Scouts, who received passes from the Army to attend the revivals, overstayed their time and returned to camp exhausted, surly, and insubordinate, which was totally out of character because they had been completely loyal and trustworthy.
More to the point, or if Gerinomo hadn't forced Chief Loco's people to accompany him, he wouldn't have had to worry about betrayal by disgruntled Chiricahuas. He might've been able to go on fighting and fleeing for years.
But what if Geronimo had done the opposite a la Robin Hood? Robbing the rich and giving to the poor, fighting the tyrannical government while helping the suffering settlers, acting nobly and never killing people unnecessarily. He probably would've gained more support as a folk hero than a villain--perhaps enough to earn a measure of freedom.
For more possible scenarios, see Was Native Defeat Inevitable? For more on Geronimo, see American Views in Geronimo and Review of Geronimo.