This paper reports Phase 4 of the Culture is Prevention Project where we validated the Cultural Connectedness Scale - California (CCS-CA) with a sample of 344 Indigenous adults in the San Francisco Bay Area, California. In Phase 3 of this project, the CCS-CA was modified from the original Canadian Cultural Connectedness Scale (CCS) developed by Dr. Angela Snowshoe and colleagues to be a better fit for the more multi-tribal communities in urban California. Both the CCS-CA and CCS consist of 29 items that measure culture on 3 sub-scales: identity, traditions, and spirituality. The project demonstrated a positive link between cultural connectedness and mental health/well-being using the Herth Hope Index. We report results similar to the original CCS study by Snowshoe et al., where we found the CCS-CA to be a valid and reliable strength-based instrument and to support the conclusion that culture is a social determinant of mental health/well-being for Indigenous/Native peoples.