The woman whose signature graces billions of US notes
Rosa Gumataotao Rios is one of the United States' most ubiquitous political figures, yet many people will probably have never heard of her.
Her name features in everyday transactions in every town and city whenever a person goes to a cash dispenser, buys bread at a shop, pays a restaurant bill or a cab driver.
But only those who carefully study the banknotes will realise who Ms Gumataotao Rios is.
This Californian woman of Mexican descent has been treasurer of the United States since 2009.
Since then, her signature has been printed on some 27 billion dollar notes.
'Part of history'
"Currency and coins are the way we touch the American public every day," she tells BBC Mundo in her Washington DC office, just a few steps from the White House.
"We are part of history."
Women have left their mark on that history in a very special way, because they have held the position of US treasurer since 1949. Six of the past 10 treasurers have also been of Hispanic descent.
Ms Gumataotao Rios says that the first woman treasurer, Georgia Neese Clark, was appointed just after the Second World War, when women's participation in the workforce increased considerably.
"It was just very courageous and probably very symbolic for President Harry S Truman to make that appointment," she says.
Since then, every US president has chosen a woman's signature to appear alongside that of the US secretary of treasury on one of the most popular currencies in the world.
Ms Gumataotao Rios explains that having women treasurers is not something that is institutionalised or has been done in order to fill a quota.
"They look at the individuals more than anything," she says. "Clark, for instance, was a banker."
She also rejects the notion that her Hispanic heritage might influence her daily activities: "Of course I am very proud to be Mexican-American, but in my role today I am an administration official."
The treasurer believes that her own previous experience in areas such as economic development, real estate and investments made her a good choice for the post at a time when the recent global financial crisis was at its height.
She also stresses that her work does not only consist of signing US banknotes, where her Mexican surname - Rios - appears next to her husband's Guamanian name, Gumataotao.
Although Treasury Secretary Jack Lew makes the final financial decisions at the treasury department, Ms Gumataotao Rios supervises the nearly 4,000 employees who work at the US Mint and the Bureau of Engraving and Printing.
She also oversees the gold reserves at Fort Knox.
Her position has historic importance: it is the only office in the treasury department that is older than the department itself. Michael Hillegas, the first US treasurer, took up his post in 1775, even before the United States acquired its name a year later on 9 September.
Ms Gumataotao Rios is aware of that historic weight, but she also knows that her real link with most Americans is created through dollar banknotes.
"My signature is all over the world", she says. "It's a sense of professional pride and of personal pride for my family."
'Very big milestone'
The first time she saw her name stamped on one of the green notes was the day after Thanksgiving in 2009.
Early in the morning, Ms Gumataotao Rios went to the Bureau of Engraving and Printing in Washington DC and was allowed to hold a freshly-printed sheet of uncut $20 notes. She was with her husband and two children, as well as the family of then-secretary Timothy Geithner, whose signature also featured.
"It was a very nice gift for my children, who were eight and 12 at the time. It's also their name on money," she adds.
Since that day, the treasurer has kept copies of each denomination, including the recently printed new $100 note and the rare $2 bill.
"To have people know that a woman is representing our government is a very big milestone that has continued to this day," she stresses.
She is not the only woman to have a prominent role in the world of finance and politics, which has traditionally been male-dominated.
For instance, in February this year, Janet Yellen became the first female chair of the Federal Reserve, while Sylvia Mathews-Burwell, the White House budget director, has just been nominated as US health secretary by President Barack Obama.
"Women are playing a very significant role in economic dialogue, not just domestically but globally as well," says Ms Gumataotao Rios.
"The more we recognise that role women play, the more it will inspire future generations to also think about a career in finance and economics."