This article was reported and written in a collaboration with ProPublica, the nonprofit investigative journalism organization.

WOLF POINT, Mont. — The faint scars on Ruth Fourstar’s arms testify to a difficult life on the Fort Peck Indian Reservation: the physical and emotional abuse at home, the bullying at school, the self-harm that sent her rotating through mental health facilities and plunged her to a remedial program from the honor roll.

A diploma from Wolf Point High School could be a ticket out of this isolated prairie town in eastern Montana. Instead, Ms. Fourstar, 17, sees her school as a dead end.

The tutoring she was promised to get her back on track did not materialize. An agreement with the high school principal to let her apply credits earned in summer courses toward graduation fell through, Ms. Fourstar said. The special education plan that the school district developed for her, supposedly to help her catch up, instead laid out how she should be disciplined.