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. The series covers a broad spectrum of individual and small unit tactics, techniques, and procedures across all six warfighting functions. Topics include the environment, specialized clothing and equipment, weapons considerations, patrolling considerations, route selection and navigation, basic avalanche hazard assessment and mitigation, crossing streams/ice, snowshoeing, winter camouflage, logistics, fire support, helicopter operations, and casualty evacuation. It stresses only the skills necessary for Marines to function in combat. Because of the rapid turnover in personnel, operational tempo, and the multitude of training commitments, the Marine Corps Mountain Warfare Training Center cannot train all Marines or units. In combat, Marines may need to learn through doctrinal references that are augmented with instruction from their unit's qualified summer and winter mountain leaders. This MCRP gives them that capability. This publication supersedes MCRP 3-35.1A, Small Unit Leader's Guide to Cold Weather Operations, dated 16 November 1990. Chapter 1 Mountain Weather Chapter 2 Command and Control Chapter 3 Movement and Navigation Chapter 4 Route Planning and Selection Chapter 5 Crossing Water Obstacles Chapter 6 Avalanches Chapter 7 Movement by Snowshoe Chapter 8 Movement by Sled Chapter 9 Casualty Evacuation in Mountain Warfare Operations Chapter 10 Mountain Patrolling Chapter 11 Fires Chapter 12 Logistics and Sustainment Chapter 13 Mountain Safety and Health Considerations Chapter 14 Cold Weather Clothing and Equipment Chapter 15 Defensive Positions and Field Fortifications Chapter 16 Bivouac Routine in Snow Chapter 17 Camouflage, Cover, and Concealment Chapter 18 Mountain Warfare Skill Sets, Capabilities, and Training Requirements Appendices: A Clothing and Equipment Weights B Patrol Order with Winter Considerations C Example of a Winter Warning Order Format D Bivouac Checklist