The purpose of this study was to measure self-efficacy of Wilderness First Responders (WFRs) over time post-certification to determine the impact of time, number of re-certifications, and frequency of skill use on self-efficacy. Previous research studied self-efficacy post-certification in Wilderness First Aid students which is a much shorter version of the Wilderness First Responder certification. This study had two parts utilizing the same survey asking participants to rate their perceived self-efficacy levels of executing different WFR skills. The longitudinal study measured self-efficacy levels in the same 10 WFRs directly after certification and again at 3 months post-certification. The broad study included 65 WFRs at any point in their certification to take the survey. To analyze results, Microsoft Excel was used to run paired t-tests to compare mean scores. Statistical significance was determined at p<0.05. Results indicated a statistically significant decrease in self-efficacy in participants after 3 months of certification. The broad self-efficacy study trends indicate self-efficacy slightly decreasing over-time, but results were not statistically significant. There was also a statistically significant increase in average self-efficacy of those who had been re-certified 3 times compared to those on their first certification. Finally, those who practiced skills seasonally or never proved to have statistically significant lower average self-efficacy scores than those who practiced skills monthly. WFR self-efficacy is incredibly important to ensure the confidence of an outdoor professional in medical scenarios and these results provide insight into factors affecting the increase and decrease of this self-efficacy. Knowing how certain factors impact WFR self-efficacy can help improve the wilderness medicine field in the future.