Discussions of what it means to be an effective outdoor leader are common in outdoor education literature (Martin et al., 2025; Smith, 2021). Research has identified core competencies (Martin et al., 2025), conceptual frameworks (Pomfret et al., 2023), and course curricula/qualifications for effective leadership (Baker & O'Brien, 2019; Seaman et al., 2017). Leadership assessment has challenged contemporary scholars (Crawford & Kelder, 2019) and the absence of rigorously designed measures of leadership leaves most programs to develop their own measures or use existing tools (Bobilya et al., 2017). This research note describes a novel methodology and statistical analysis for measuring leadership outcomes. The Outdoor Situational Leadership Rubric (OSLR) was designed and tested in this study. The OSLR was created to measure outdoor leaders' ability to apply situational leadership theory. Generalizability theory was used to gather reliability and validity evidence for the rubric. This study demonstrates that more research is needed to examine the psychometric properties of the OSLR. However, it describes a promising methodology for practitioners to demonstrate program value, exposes possible shortcomings of situational leadership theory and introduces a novel statistical technique to the field of outdoor education.