Yellowstone fans are abuzz with a theory that could shake up Taylor Sheridan’s entire Western universe: Chief Thomas Rainwater, played by Gil Birmingham, might be secretly connected by blood to another major character.

This revelation would not only deepen the show’s mythology but also add complex new layers to the ongoing struggle over land, power, and legacy.

Rainwater has been a compelling presence since the show’s debut, serving as both adversary and occasional ally to John Dutton. Despite his commanding role as leader of the Broken Rock Reservation, some fans have long wished for more exploration of his backstory. That wish may soon be granted, thanks to clues from Yellowstone’s prequels—especially 1923.

In 1923, viewers followed Tiana Rainwater, a possible ancestor of Thomas, and her tragic romance with Pete Plenty Clouds. Although Pete was killed before they could start a new life together, their brief relationship may have resulted in Tiana becoming pregnant.

If so, this child could be a direct ancestor of Thomas Rainwater, explaining his presence in the modern-day Yellowstone world. The connection could even mean Rainwater and his loyal aide, Mo, are distant relatives, given the shared family names.

This would reframe their close partnership as a bond rooted not just in friendship, but family.

Tiana’s story, left open-ended in 1923, adds a sense of mystery to Rainwater’s origins. We know from Yellowstone that Rainwater was adopted and raised away from the Broken Rock Reservation, even believing he was of Mexican descent for much of his life. It’s possible Tiana moved south after Pete’s death, raising their child away from her tribal roots to escape her painful past.

If future prequels like the upcoming 1944 series explore this thread, we may finally see the missing links in Rainwater’s family tree.

But the speculation doesn’t stop there. Some fans believe Rainwater could even be distantly related to the Duttons themselves. Perhaps, during the westward expansion depicted in 1883, a Dutton descendant had a child with a Native woman, with that lineage eventually leading to Rainwater.

If true, the battle over land would become not just a clash of cultures but a deeply personal family conflict, with Rainwater caught between two worlds and two legacies.

Other theories suggest Rainwater could share ancestry with Rip Wheeler, the Duttons’ fiercely loyal enforcer. Rip’s own past is shrouded in mystery, and a shared bloodline with Rainwater would make for explosive storytelling, forcing both men to confront their identities and loyalties.

There’s also the enigmatic Angela Blue Thunder, Rainwater’s adviser, who may know more about his origins than she lets on. Should she reveal a hidden connection between Rainwater and another major character, it could upend alliances and power dynamics within the series.

Ultimately, a shocking familial tie would fundamentally transform Yellowstone’s emotional core. Sheridan’s universe is built on questions of identity, heritage, and the burdens of history.

If Thomas Rainwater’s roots prove tangled with those of the Duttons or other key players, it would bring those themes into sharper focus—making the struggle for Yellowstone’s land not just a fight for survival, but a battle for the soul of a family, a people, and a legacy.