Asked to list her achievements, she replies, "I made a contribution to something a very large number of people achieved." But if she wished, she could stand on the riverbank and take some credit for the wild condition of not only her beloved stretch of the Rio Grande, but also the Chama River in New Mexico and California's Merced River. She contributed to the San Juan Basin and El Malpais wilderness campaigns in New Mexico, the Aravaipa and Arizona Desert and Arizona Strip wilderness campaigns in Arizona, and California's Ventana Wilderness as well as the California Desert Protection Act, which preserved more than 1.4 million acres in a single stroke. Among her personal favorites is the preservation of the hoodoo rock in three tiny wild areas in northern New Mexico called the Bisti Badlands.

She's also served on the boards of directors of the League of Conservation Voters and The Partnership Project, a behind-the-scenes coalition of the 21 biggest environmental groups. Fair to say, personal connections help. During the 1990s, when Bill Clinton was president, for instance, Sease could "be found brainstorming with the other female power players in the environmental movement at a networking luncheon held in Washington, D.C., every six weeks," E: the Environmental Magazine reported in 1997. Those power lunches included Carol Browner, head of Clinton's Environmental Protection Agency, and Katie McGinty, head of Clinton's Council on Environmental Quality. Around that time, Sease's official lobbying helped push the Clinton administration to toughen regulations on soot and smog -- a crackdown that survived President George W. Bush's efforts to roll back many regulations.

The environmental movement, especially in D.C., is also a lifestyle and a social setting. Sease remarried, to Russell Shay, then a fellow Sierra Club lobbyist. He worked on wilderness legislation with her and spent almost a decade as an aide in the House and Senate, specializing on public lands and environmental matters. They live in a rowhouse -- a narrow two stories and a basement -- in the charming Capitol Hill neighborhood, a favorite for members of Congress, near urban parks, a Shakespeare theater, tidy strips of restaurants and shops. She often rides a bike to work, but she's hesitant to bike home at night because it doesn't feel that safe after dark. As she says, "It is the city." She has no kids and fills any spare moments with creative hobbies: She's become a painter, a woodworker and an urban gardener.

In the springtime, from her office window in another building in the neighborhood, she can see the cherry blossoms in a small park. (The Sierra Club needs more space, however, so soon she'll move to a building where her window will look out on an alley.) She's decorated her office with Western art and artifacts and quirky mementoes. She built the conference table out of an old slab of elm and did the turquoise inlay. A mashed hubcap is displayed on the wall: She had a fender-bender while driving a 15-passenger van on a political tour of the California desert, and Sierra Club volunteers gave her the hubcap as a souvenir.

No longer such an overt buckaroo, she wears dresses or jeans to work, and keeps a suit hanging on the back of her office door for important meetings with politicians. Even in the suit, she sticks to "sensible shoes" -- flat with rubber soles for walking across the marble floors of the monumental buildings in the Capitol complex. She walks with a slight limp; the joints of one foot are fused, part of the polio aftermath. She still likes the flash of Navajo silver, turquoise and coral jewelry, some of which she buys in the Department of Interior's Native American crafts store.

She works 40 to 70 hours per week. Her favorite D.C. habitats include the Hart Senate Office Building: "It's spare, designed to be monumental yet accommodating to humans, very satisfying, and I love the Calder mobile in the center of it." She likes to take refuge in the 130-year-old Capitol Grotto, designed by the Capitol's landscape architect, Frederick Law Olmsted -- a small fountain, four benches and intricate brickwork in a grove of trees where few tourists go. She sits there between meetings, reading email on her iPhone.