She helped build schools, taught Amazon settlers the value of the rain forest and helped them fight for their rights in the face of land grabbing and wanton environmental destruction.
And for this, she paid with her life.
"She was tough, smart and intensely political. It was precisely her fervent work on behalf of the poor that got her killed. None of this little nun bit. She was like a Mack truck," Ms. Stang's brother David explains.
On Feb. 12 2005, a gunman fired six bullets into her 73-year-old body at close range on a muddy stretch of road in the heart of the jungle.
Like the assassination of Chico Mendes, the rubber tapper and union leader shot dead in 1988, Ms. Stang's killing focused international attention on land struggles in the Amazon, where powerful ranchers using forged papers routinely force settlers from their homes and where nearly 1,000 union leaders, activists and clergy members have been killed over the past 30 years.
Ms. Le Breton, a British journalist who has written a number of important books about Amazon issues, describes in this terse, highly readable narrative how a scrappy little nun from Dayton, Ohio, stumbled into Brazil's wild west.
The biography follows Ms. Stang from her Norman Rockwell upbringing as the fourth of nine children in a stern German-Irish Catholic family to her convent years among the Sisters of Notre Dame de Namur to her early work with Mexican migrants in Arizona.
Ms. Stang then moved on to the backwaters of Brazil, where she and a handful of other young American nuns arrived in Rio de Janeiro in 1966, while the country was still ruled by a military dictatorship.
Ms. Le Breton provides wonderful details, such as how Ms. Stang came to lose her habit -- removing it only to keep it clean on the country's dry dusty roads and then finding the local bishop preferred the young nuns without them.
Ms. Le Breton also does a nice job of explaining how Ms. Stang's work with the poorest led her to Liberation Theology, which reinterprets the Gospels to focus on Christ's work for the poor.
The movement was sweeping Latin America at the time, despite Vatican opposition that led the church to censure of a number of prominent advocates.
Liberation theology also upset powerful interests in Brazil.
"People who worked for human rights and for the settlers' rights to the land were labeled subversive and the government had them hunted down," Sister Joan, one of Ms. Stang's oldest friends, explains in the book.
"Death was a price that many paid for envisioning a just society. Everyone who worked with the poor was called a communist. Dot was called a communist."
Toward the end of her life, Ms. Stang was promoting Sustainable Development Projects, a zoning mechanism under Brazilian law that allows settlers to claim land in exchange for promising to develop it in a sustainable manner, without cutting more than a small portion of trees.
This brought her into direct conflict with a pair of ranchers who claimed the land as their own.
Ms. Le Breton recreates these scenes from the perspective of Ms. Stang and her killers, but doesn't fully explore the motivations of these rich and powerful ranchers.
Although two ranchers were charged with ordering her death and one has been convicted, their motivations remain obscure.
BY THE BOOK
TITLE: The Greatest Gift
AUTHOR: Binka Le Breton
PUBLISHER: Doubleday (256 pages, $21.95)