Culturally appropriate, valid and reliable measures are critical to assessing how interventions impact health. There is a tension between measures for specific cultural settings versus more general measures that permit comparisons across samples. We illustrate a feasible approach to measurement selection, adaptation and testing for a study of brief interventions to prevent suicide among American Indian youth ages 10-24. We used a modified Nominal Group Technique (NGT) with N = 7 Apache Community Mental Health Specialists (CMHS') to elicit priority impacts of interventions under study. We then tested the reliability and validity in N = 93 youth at baseline. The NGT results included selection of alternative measures, item removal and addition, and creation of a local well-being index. Measurement testing indicated excellent to good internal consistency (α: 0.82-0.96) and strong construct validity. Study results demonstrate a feasible approach to balancing cultural specificity and generalizability while producing valid and reliable measures to use in an intervention trial. (PsycInfo Database Record (c) 2022 APA, all rights reserved).