SANTA MARIA QUIEGOLANI, Mexico — Women in this Indian village high in the pine-clad mountains of Oaxaca rise each morning at 4 a.m. to gather firewood, grind corn, prepare the day’s food, care for the children, and clean the house.

But they aren’t allowed to vote in local elections, because — the men say — they don’t do enough work.

“I’d like to see the men here make tortillas, just for one day, and then tell me that’s not work,” said Eufrosina Cruz, describing the hours-long process of cleaning, soaking, cooking, and milling the corn, shaping the flour into flat disks, and collecting the firewood to heat the clay and brick hearths on which most women cook.

It was here, in a village that has struggled for centuries to preserve its Zapotec traditions, that Ms. Cruz, 27, decided to become the first woman to run for mayor — despite the fact that women aren’t allowed to attend town assemblies, much less run for office.

The all-male town board tore up ballots cast in her favor in the November 4 election, arguing that as a woman, she wasn’t a “citizen” of the town. “That is the custom here, that only the citizens vote, not the women,” the town’s deputy mayor, Valeriano Lopez, said. Rather than give up, Ms. Cruz has launched the first serious, national-level challenge to traditional Indian forms of government, known as “use and customs,” which were given full legal status in Mexico six years ago in response to Indian rights movements sweeping across Latin America.

“For me, it’s more like ‘abuse and customs,'” Ms. Cruz said as she submitted her complaint in December to the National Human Rights Commission. “I am demanding that we, the women of the mountains, have the right to decide our lives, to vote and run for office, because the constitution says we have these rights.”

Mr. Lopez acknowledged that votes for Ms. Cruz were nullified, but claims they added up to only 8 ballots of about 100 cast in this largely unpaved village of about 1,500 people.

Ms. Cruz says she was winning — and wants the election to be annulled and held again, this time with women voting.

Ms. Cruz has received some support from older men, who by village law lose their political rights when they turn 60. Some younger men also say the system must change and give women more rights.

But the male leaders are refusing to budge. “We live differently here, senor, than people in the city. Here, women are dedicated to their homes, and men work the fields,” the secretary of the all-male town council, Apolonio Mendoza, told a visiting reporter.

Ms. Cruz decided to escape that life after she saw her 12-year-old sister given to an older man in a marriage arranged by her father. The sister had her first child at 13 and has since borne seven more. Ms. Cruz was 11, and “I didn’t even know what a bus was then.” She traveled to the nearest city to enroll in school, live with relatives, and support herself through odd jobs, eventually graduating from college with a degree in accounting.

She is single, and in a village culture where most women wear skirts, she wears pants. Because her village has no formal jobs for women, she works as a school director in a nearby town, and returns to Quiegolani most weekends. That, authorities say, disqualified her from running for mayor because she wasn’t a full-time resident.

Ms. Cruz figured her case for annulling the elections was solid — after all, Mexico’s constitution guarantees both men and women the right to vote. She went first to the Oaxaca state electoral council, then to the state congress. After both upheld the election, she took her fight to the commission in Mexico City.

“I am not asking anything for myself. I am asking on behalf of Indian women, so that never again will the laws allow political segregation,” Ms. Cruz wrote to the commissioners, who may take months to investigate the case, and who could recommend that state authorities protect women’s rights to vote or hold office. She says she’ll go higher, to federal electoral authorities, if necessary.