A little girl's promise to her grandmother has meant nine million dollars in goods and services for Native Americans on a South Dakota reservation.

Today, a half-century later, Rochelle Ripley is keeping that promise, working alongside the Lakota tribe with volunteers to improve their health and education, and rebuild homes for the Lakota people.

Ripley's grandmother was full-blooded Lakota and entertained her as a child with stories of life on the reservation.

"My grandmother was my world," Ripley told CNN. "She asked me if I would go back home and help our people when I grew up."

Today, a half-century later, Rochelle Ripley is keeping that promise, working alongside the Lakota tribe with volunteers to improve their health and education, and rebuild homes for the Lakota people.

Ripley's grandmother was full-blooded Lakota and entertained her as a child with stories of life on the reservation.

"My grandmother was my world," Ripley told CNN. "She asked me if I would go back home and help our people when I grew up."

Ripley travels to her ancestor's homeland four times each year from her home in Glastonbury, Connecticut, since creating a nonprofit called Hawkwing. She brings in donations and coordinates volunteer efforts to help her grandmother's people on the Cheyenne River Sioux Reservation in South Dakota.

She recently worked with a national teachers' sorority to provide a bookmobile, delivering reading materials to kids scattered throughout the 4,200-square-mile reservation. Ripley also rallies volunteers to spend two weeks every year building and repairing houses — termed the "most urgent need" by the Lakota Tribal Chairman. Her nonprofit supports medical and dental clinics and mental health counseling. It has also partnered with Vitamin Angels to provide $300,000 worth of vitamins to children and mothers.

Ripley and Hawkwing have created a food pantry and arranged for outside shipments of fresh produce – and even delivered greenhouses to help the Lakota grow their own organic crops.

Her work has made Rochelle Ripley one of CNN's Top Ten Heroes of the Year. You can vote for her as your choice for Hero of the Year at CNNHeroes.com. The network will announce the winner at their annual televised award show December 6, and present the 2015 winner with $100,000 for continuing his or her good work.

(WATCH the CNN video below)