By ELISSA STOHLER

When ABC News first met little Tashina Iron Horse, she was 5 years old, a chatty and vivacious kindergartener. Now she’s 6, in the first grade, and she tells us she wants Justin Bieber to be her boyfriend. If she could, she’d ask President Obama for “Fresh water…and bubble gum…and a backpack.” She wants to grow up to be a police officer, a career choice inspired by her mother Bobbie, who works long hours as a security guard.

Tashina lives on the Pine Ridge Indian Reservation, where most of the 30,000 to 40,000 residents identify as Oglala Lakota Sioux and boast of a rich cultural history and deep-seeded spirituality. Located in the southwest corner of South Dakota, Pine Ridge is one of the 565 federally recognized Indian Nations in the United States. It is also one of the poorest.

Young Tashina Iron Horse is a competitive pow wow dancer. (credit: Elissa Stohler/ABC News)

Pine Ridge residents live amid poverty that rivals that of the third world. Forty-seven percent of the Pine Ridge population lives below the federal poverty level, 65 percent to 80 percent of the adults are unemployed, and rampant alcoholism and an obesity epidemic combine with underfunded schools to make it a rough place to grow up. Tashina lives in government housing in Manderson, 30 minutes north of downtown Pine Ridge. She lives with her grandmother, parents, siblings and uncles – sometimes up to 19 people live in the three-bedroom house, which has seen better days.

In the decades following President John F. Kennedy’s pledge to fund public housing projects on American Indian reservations, a construction boom began in Pine Ridge. Today, most of these units built in the 1970s and 1980s are in varying degrees of disrepair – a result, critics say, of steep cuts to the Housing and Urban Development budget made by President Ronald Reagan in the 1980s. Public housing dollars today are largely spent battling black mold in reservation housing rather than constructing new homes.

Amid the despair, there are youth across the reservation — like Tashina — who are breaking through the hopelessness with huge dreams and powerful stories.

So that she can be a competitive dancer at the pow wows, Tashina sports beautifully hand-crafted outfits made by her Uncle Matthew. Matthew is a senior in high school who lovingly hand-sews and beads Tashina’s pow wow regalia: shawls, moccasins, hair pieces, and dresses. At the pow wows, Matthew is constantly at Tashina’s side: practicing with her and helping her get into costume.

Learn more about Tashina and the challenges she and other Pine Ridge children face Friday at 10 p.m. ET on “Hidden America: Children of the Plains,” a 20/20 special. Check out a sneak peek — Tashina teaches Diane Sawyer some of her moves — below.