The Outdoor Adventure Leadership Experience (OALE) is an outdoor health promotion initiative primarily designed for youth. This program was developed through community-based participatory research in a First Nations Community in northern Ontario: Wiikwemkoong Unceded Territory. It is a 9- or 10-day intensive program involving a wilderness canoe expedition homeward through the traditional territory of Wiikwemkoong. The purpose of this study was to evaluate the impact of the OALE on youth well-being, using a culturally appropriate measure of health: The Aboriginal Children's Health and Well-being Measure (ACHWM©). A pre- and post-intervention study design was used to assess the impact of the OALE on health and well-being. Twenty-eight participants completed both the ACHWM and the Global Health Rating (GHR) instruments before and after the OALE intervention. In total, 68% of participants reported higher ACHWM scores after the OALE ([Delta] = 3.9, p = 0.014). There were improvements in the Medicine Wheel quadrants score of the ACHWM (spiritual, emotional, physical, and mental). Although 25% of participants had higher scores on the GHR, this did not reach statistical significance (p = 0.55). However, this study highlights the value of evaluating local programming in a culturally-relevant way. Using the ACHWM, it was demonstrated that there was a significant change in the well-being of the OALE youth participants; this was something that the GHR was unable to capture. Thus, the ACHWM appears to be sensitive to short-term changes in health. More research is needed to confirm the specificity and sensitivity of the ACHWM in different populations and contexts.