SANTA FE, N.M. -- Stewart Udall, who sowed the seeds of the modern environmental movement as secretary of the interior during the 1960s and later became a crusader for victims of radiation exposure from the government's Cold War nuclear programs, died Saturday. He was 90.
A statement from Udall's family, released through the office of his son, Sen. Tom Udall, D-N.M., said he died of natural causes at his home in Santa Fe, surrounded by his children and their families.
Udall, brother of the late 15-term congressman Morris Udall, served six years in Congress as a Democrat from Arizona, and then headed the Interior Department for eight years under Presidents Kennedy and Johnson. His son Tom and nephew Mark also became congressmen, then both were elected to the Senate in 2008.
Under Stewart Udall's leadership from 1961 through 1968, the Interior Department aggressively promoted an expansion of public lands and helped win enactment of major environmental laws, including ones to protect endangered species.
Udall helped write several of the most far-reaching pieces of legislation, including the Wilderness Act of 1964, which protects millions of acres from logging, mining and other development.
"I never lost an argument with the budget people under either Kennedy or Johnson. If you had a new national park or a new policy on wilderness or something on wild rivers ... they'd say, `Go ahead. It's a good idea,"' Udall once said in an interview.
More than 60 additions were made to the National Park system during the Udall years, including Canyonlands National Park in Utah, North Cascades National Park in Washington, Redwood National Park in California and the Appalachian National Scenic Trail stretching from Georgia to Maine.
In a 1963 book, Udall warned of a "quiet conservation crisis" from pollution, overuse of natural resources and dwindling open spaces. He appealed for a new "land conscience" to preserve the environment.
"If in our haste to 'progress,' the economics of ecology are disregarded by citizens and policy makers alike, the result will be an ugly America," Udall wrote. "We cannot afford an America where expedience tramples upon esthetics and development decisions are made with an eye only on the present."
After leaving government service, Udall taught, practiced law and wrote books. In 1979, he left Washington to return home to Arizona. In doing so, Udall began another career -- leading a legal battle against the government he had once served as an influential insider.
Udall helped bring a lawsuit against the government on behalf of the families of Navajo men who suffered lung cancer in mining uranium for the government. Another lawsuit sought compensation for people who lived downwind from aboveground nuclear tests in Nevada during the 1950s and early 1960s.
The lawsuits failed in court, and Udall said the experience left him angry and discouraged.
"The atomic weapons race and the secrecy surrounding it crushed American democracy," Udall said in a 1993 interview with The New York Times. "It induced us to conduct government according to lies. It distorted justice. It undermined American morality."
But the lawsuits eventually produced results. They provided a mountain of evidence for congressional investigations into the safety of the nation's nuclear weapons complex. And in 1990, the Radiation Exposure Safety Act was enacted to compensate thousands of Americans. Udall helped write the measure and lobby for its passage.
In a 1994 book, Udall reassessed the actions of his own generation and criticized the rush to develop the atomic bomb, its use against Japan and decades of government secrecy in what he described as "our tragic affair with the atom."
Udall, who moved to New Mexico in 1989 to live near family, said "there was a lot of catharsis" in the book.
"So many people of my generation who served in the government were prisoners of the Cold War culture, still are. But maybe there is value in somebody like me breaking away," he said. "What I'm trying to be is provocative. I'm trying to encourage my children's generation and the other ones coming to return to basic American principles."
On election night 2008, Stewart Udall looked on proudly from a seat on the podium as son Tom gave his acceptance speech to a rowdy crowd of 1,000 at an Albuquerque hotel. A five-term congressman, the younger Udall was elected to the Senate seat that had been held by retiring six-term GOP incumbent Pete Domenici.
On the same day, Morris Udall's son Mark, also a veteran congressman, was elected to the Senate from Colorado, while Sen. Gordon Smith, a Republican whose mother was a Udall, lost a bid for a third term in Oregon. Another Udall cousin, Steve, unsuccessfully sought a seat in Congress from Arizona in 2002.
"I wouldn't call it a dynasty," Stuart Udall once said. "We're all pretty individualistic."
Udall, born in St. Johns, Ariz., on Jan. 31, 1920, was raised on a farm in the desert country near the Arizona-New Mexico line, an area settled in 1879 by Mormons led by his missionary grandfather. The Udalls became one of the most prominent families in the state. His father was a justice on the Arizona Supreme Court.
After World War II broke out, Udall enlisted and served as a gunner on a B-24 bomber in Italy. He returned to Arizona and finished school, receiving a law degree in 1948 from the University of Arizona. He and brother Morris opened a law practice in Tucson.
In 1954, an incumbent Democratic congressman retired and Udall won the seat in the U.S. House of Representatives representing a district that included all but the Phoenix area. He backed liberal causes in Congress, including civil rights legislation, federal aid to integrated public schools. And as a Westerner, he supported federal public works project such as dams for hydroelectric generation.
Udall worked with then-Sen. Kennedy in 1959 on labor reform legislation and helped Kennedy secure the support of Arizona's delegates to the 1960 Democratic National Convention -- votes considered safe for Johnson. Udall won re-election in 1960 but gave up the seat to accept the interior secretary appointment. Udall's brother, Morris, succeeded him in Congress by winning a special election.
Udall married Ermalee Webb of Mesa, Ariz., on Aug. 1, 1947. She died in 2001.
He is survived by six children -- Tom Udall, Scott Udall, Lynn Udall, Lori Udall, Denis Udall and Jay Udall -- and eight grandchildren. The family said a memorial will be held later this year in Santa Fe.