Marine Corps Reference Publication (MCRP) 3-35.1A, Small Unit Leader’s Guide to Mountain Warfare Operations, is a reference for all Marine leaders (team through company) to use when conducting operations in mountainous terrain, snow, cold weather, and/or high altitude. This publication is to be used in conjunction with the Marine Corps Warfighting Publication 3-35.1, Mountain Warfare Operations, and its other associated MCRPs 3-35.1B, Mountain Leader’s Guide to Winter Operations; 3-35.1C, Mountain Leader’s Guide to Mountain Warfare Operations; and 3-35.1D, Cold Region Operations.