 This study involves adaptation, implementation, and rigorous evaluation of a family-based program designed to prevent early initiation of substance use on a Northern Plains Indian reservation. The program, Thiwáhe Gluwášakapi, is a cultural adaptation of the Iowa Strengthening Families Program for Parents and Youth 10-14. Youth and their parentscaregivers will participate in weekly group sessions for 7 weeks and complete pre- and post-intervention surveys assessing a variety of risk and protective factors and youth outcomes. The evaluation design will allow the assessment of the effectiveness of different components within the program. 