Marine Corps Reference Publication (MCRP) 3 35.1B, Mountain Leader's Guide to Winter Operations, is a reference for trained winter mountain leaders to use during operations in snow. This publication is to be used with the Marine Corps' mountain warfare and cold weather series doctrinal publications. It contains winter operations tactics, techniques, and procedures covering combat ski instruction and skills, crawls, firing positions, avalanche hazard assessment and mitigation, and crossing frozen waterways. It also covers, snow tracking and deception, skiborne patrolling considerations, and over-the-snow vehicle employment. Focusing on a standard method of instruction, this publication stresses only the cold weather skills necessary for Marines to go into combat.