Three American Indian tribes that received Tribal Juvenile Detention and Reentry Green Demonstration (“Green Reentry”) grants were evaluated: the Hualapai Indian Tribe, the Mississippi Band of Choctaw Indians, and the Rosebud Sioux Tribe. Throughout their grant periods, the grantees received training and technical assistance from the Tribal Juvenile Detention and Reentry Resource and Technical Assistance Center, managed by the Education Development Center. The report summarizes the implementation experiences and program impact of the three grantees, as documented by a cross-site evaluation. After a brief literature review that provides context for the Green Reentry initiative the authors describe the initiatives and cross-site evaluation methodology; present the evaluation findings, including descriptions of the programs and implementation experiences; provide outcome evaluation findings, including qualitative findings on perceived impact and quantitative findings on the impact on recidivism; and provide recommendations for practice and policy, and outline future research directions. The Green Reentry grantees were found to be extremely successful at implementing a diverse set of green projects and intensively serving youth. Despite encountering numerous implementation challenges, interviewees reported that the programs were very successful at developing strong relationships with youth, teaching them new skills, and exposing them to a new way of thinking. Findings from the recidivism analysis suggest that Green Reentry participants had lower short-term rates of recidivism than comparable youth not enrolled in the programs. The programs built close networks among tribal agencies and youth-serving organizations on the reservations where they worked, with many staff and stakeholders feeling that service coordination for youth had improved as a result of their efforts.