As the backbone of the of the NOLS instructor notebook series the Leadership Educator Notebook (LEN) has proven to be an invaluable resource to NOLS instructors and outdoor educators the world over. Covering concepts ranging from communication to developing judgment the LEN provides a leadership progression that can be taught in both back-country and front-country classrooms. Based on the NOLS model the LEN is designed as a resource to help outdoor educators develop their signature leadership style. It is a virtual toolbox for teaching leadership, and can be used as a means to spark personal growth as a leader or to help improve in the coaching of students and teaching of formal classes.First Developed in 1998 the LEN is the culmination of NOLS’ collective wisdom on leadership cross-checked with conventional leadership theory from the fields of psychology, business, military, and religion. The resulting text defined expected outcomes for leadership development on a NOLS expedition, and found relevance in the broader leadership community. When NASA selected NOLS as their vendor for astronaut leadership training, this leadership teachers' guide was one of the deciding factors.