Wilma Mankiller, who as the first woman to be elected chief of a major American Indian tribe revitalized the Cherokee Nation’s tribal government and improved its education, health and housing, died Tuesday at her home near Tahlequah, Okla. She was 64.

The cause was pancreatic cancer, said Mike Miller, a tribal spokesman.

Ms. Mankiller was the Cherokee chief from 1985 to 1995, and during her tenure the nation’s membership more than doubled, to 170,000 from about 68,000.

While many Cherokees live in a 14-county area around the tribal capital of Tahlequah, in eastern Oklahoma, its members are spread throughout the 50 states. The current tribal membership is 290,000, making it the second-largest tribe in the country after the Navajo.

Ms. Mankiller was admired for her tenacity, having fought off two serious diseases, lymphoma and a neuromuscular disorder called myasthenia gravis; recovered from kidney failure that would have killed her had not an older brother given her one of his kidneys; and survived a head-on automobile collision in 1979 that forced her to endure 17 operations and years of physical therapy.