Louise Erdrich (photo by Allen Brisson-Smith for The New York Times)

The prize, which will be awarded during the National Book Festival on Sept. 5, is given to writers with "unique, enduring voices" whose work addresses the American experience. Past winners include John Grisham, Toni Morrison and E.L. Doctorow.

Ms. Erdrich was born in Little Falls, Minn., in 1954, to a German-American father and a mother who is half Ojibwe. In a career that covers more than three decades, she has written 14 novels, as well as poetry, children's books, short stories and nonfiction.

"Louise Erdrich has portrayed her fellow Native Americans as no contemporary American novelist ever has," James H. Billington, the Librarian of Congress, said in a statement announcing the prize. "Her prose manages to be at once lyrical and gritty, magical yet unsentimental, connecting a dreamworld of Ojibwe legend to stark realities of the modern-day."

In an email interview, Ms. Erdrich, who has won the National Book Award and the National Book Critics Circle Award, said such recognition felt like "an out of body experience."

"It seems that these awards are given to a writer entirely different from the person I am — ordinary and firmly fixed," she wrote. "Given the life I lead, it is surprising these books got written. Maybe I owe it all to my first job — hoeing sugar beets. I stare at lines of words all day and chop out the ones that suck life from the rest of the sentence. Eventually all those rows add up."

Ms. Erdrich, a member of the Turtle Mountain Band of Chippewa, said that she never set out to write about the American experience or her own mixed heritage, and simply aimed to write compelling stories.

"I don't write from a compulsion to provide for the reader a Native American, Great Plains, or for that matter German-American experience," she said. "I write narratives that compel me, using language that reverberates for me."