Nina Otero-Warren's Spanish conquistador ancestors dramatically altered the social and political landscape in Santa Fe more than three hundred years before she herself made waves as a twentieth-century suffragist, educator, and businesswoman. Nina Maria Adeline Isabel Emilia Otero was born in Las Lunas, New Mexico, in 1881. Her conservative, prosperous parents traced their heritage to eleventh-century Spain. As Nina grew up, newly built railroads began bringing Anglos, commerce, and rapid change to her hometown. She attended Maryville College in Saint Louis from 1892 to 1894, then moved to Santa Fe when her uncle Miguel Otero was appointed territorial governor of New Mexico. There, she eventually married Lieutenant Rawson Warren in 1908. The marriage was short-lived, and Nina remained childless and independent for the rest of her years, though she helped raise her siblings after her mother's death. She focused on her professional life and politics, becoming one of New Mexico's most admired female leaders.

By 1914, Otero-Warren was drawn to the women's suffrage campaign in New Mexico when Alice Paul's Congressional Union (forerunner of the Woman's Party) sent talented organizers into the state. Otero-Warren soon rose to leadership ranks in the state Congressional Union (CU), rallying support among both Spanish- and English-speaking communities. Her family connections helped as well, as she was the niece of the popular head of New Mexico's Republican Party. Although New Mexico never legalized women's right to vote prior to ratification of the 19th Amendment, Otero-Warren's patient but incessant badgering of the New Mexico congressional delegation convinced them to vote in favor of the amendment in 1920.

From 1917 to 1929, Otero-Warren served as one of New Mexico's first female government officials, as Santa Fe Superintendent of Instruction, and chair of the State Board of Health. By 1922, she won the Republican Party nomination to run for the U.S. House of Representatives. Although she lost her bid for Congress, a few years later she was appointed as state director of the federal Civilian Conservation Corps (CCC) by President Franklin Delano Roosevelt.

Otero-Warren's contributions to her community were not just in the political realm. She headed efforts to preserve historic structures in Santa Fe and Taos and built close ties with the artists, writers, and intellectuals who congregated in the area during the 1930s and 1940s. She was instrumental in renewing interest in and respect for Hispanic and Indian culture, which had for a time faced scorn and ridicule.

Otero-Warren and a close friend purchased a large ranch outside Santa Fe that they called "Las Dos." In the 1930s, Otero-Warren's adobe house overlooking the Sangre de Cristo Mountains attracted visitors and inspired artists and writers. Her own book, Old Spain in Our Southwest (1936), recorded her memories of the family hacienda in Las Lunas. She continued her life at Las Dos as a businesswoman, educator, writer, and political activist until her death in 1965.