"The Turtle's Beating Heart," the title of this arresting family memoir by former Kansas poet laureate Denise Low, was inspired by a story she heard from an Arikara Indian woman whose grandmother once fed her the heart of a just slaughtered turtle, whose "hearts keep beating long after separation from their bodies." This, Low writes, "was an old ceremony for a woman's coming of age. The woman never forgot the lesson of Turtle's strength, as she felt the sensation of the moving heart in her mouth, throat, stomach, and gut."

Well into adulthood, Low came into the realization that her maternal grandfather, Frank Bruner Jr., was a Delaware (Lenape) Indian, part of a diaspora of that tribe, whose members were present at the so-called sale of Manhattan Island to the Dutch and were later driven, in fits and starts, over centuries, westward to various decreasingly verdant landscapes. As a child, she often heard vague, uneasy references to Indian ancestry, and it is that secrecy, even more than the ancestry itself, that inspired the quest that led to this book. "Historic trauma is the term that suggests long-lasting effects of grief through generations, and it frames my account," she writes. "Restoring my family's suppressed ethnic background adds a small part to the marginalized Delaware history."

Low's exploration of her parents', grandparents' and great-grandparents' lives leads her to a better understanding of her own childhood and self. But more important than her personal odyssey is the broader understanding that she shares about how American Indian ancestry, especially when it lacks the blood quantum proof that allows a person official tribal membership, can be a mixed blessing. The kind of pride a modern American might feel in it is often the exact opposite of the emotions it evoked in their parents and grandparents.

That is true for Low's mother, who referred to her own father's Indian heritage only sparsely and with embarrassment, bitterly blaming it for his late-in-life alcoholism and melancholy. And yet, Low realized after her mother's death how many things in her mother's life were inspired, often unconsciously, by her father's Delaware ancestry and culture.

Low remembers Bruner, who died when she was a child, as a silent, kind man who taught her to play cards and seemed shaped and bent by a host of mysteries. As a child, she could not have guessed at those; as an adult, learning of his Indian ancestry, it all made melancholy sense. Bruner, like many Indians who sought to assimilate early in the 20th century to escape anti-Indian contempt and violence, suffered deeply for his life of denial.

While Low's exploration makes for a powerful family memoir, it wavers as history. Her memories of her grandfather, as well as those of other ancestors, are slim and blurry, and during his life he said little and wrote even less.

"Silence is a common symptom of the trauma of Native displacement," she writes. However true that may be, it makes her analysis of his emotions and motivations almost pure speculation, and perhaps more linked to her own modern psychology than to his own.

That's a problem that any of us might run into, climbing up into our family tree on Ancestry.com or in old family papers and elders' stories. We learn a lot that also tells us some things about ourselves, but there is also a cavernous silence there, and mysteries that must always remain so.

Still, Low does Americans with Indian ancestry a valuable service by illuminating the unique and often terrible circumstances and choices their forebears faced. It is that haunting sense of disturbance, like the still-beating heart of the turtle in the gut, that is worth acknowledging and honoring.

Pamela Miller is a Star Tribune night metro editor.

The Turtle's Beating Heart
By: Denise Low.
Publisher: Bison Books, 200 pages, $24.95.