The purpose of this study was to assess the efficacy of the proposed Outdoor Leader Career Development Model (OLCDM) through the development of the Outdoor Leader Career Development Inventory (OLCDI). I assessed the reliability and validity of the OLCDI through exploratory factor analysis, principal component analysis, and varimax rotation, based on a sample of 594 self-identified outdoor leaders. The analysis resulted in a 27-item instrument consisting of five subscales with alpha values of 0.75, 0.71, 0.68, 0.66, and 0.85, respectively. Renaming the five stages of career development and clarifying developmental attributes allowed for modification of the OLCDM. I used a factorial ANOVA to explore potential relationships between stages of development and gender based on educational level, years of work experience, and employment status. I also discuss implications for professional practice.