When forest harvesting equipment moves across a cutblock, soil compaction and/or rutting can result. Forest practitioners are therefore concerned about the long-term effects of harvesting on forest soil health, water quality, and tree growth. The purpose of this handbook is to provide practical advice to forestry contractors and equipment operators, and their field supervisors, about the risk of damage to forest soils during harvesting operations, and how to avoid it. The opportunity to protect forest soil occurs at each step of the forestmanagement process, from harvest planning to field layout to harvesting and post-harvesting activities. Operators of forestry equipment, harvesting contractors, and field supervisors are vital links in this process. To help identify when the health of forest soil is at risk, this handbook offers a brief introduction about forest soils, and explains why and how soil is susceptible to damage. The soil terminology used is defined in a glossary along with other equipment related terms (Appendix I). For harvesting contractors and equipment operators, the handbook explains how visual indicators like landscape features and tree species can be used to estimate soil moisture, and offers simple field tests to help them anticipate when soils become at risk. For contractors, equipment features that influence soil compaction and rutting are discussed, and operating techniques to reduce soil damage are suggested. For field supervisors, harvest scheduling options that minimize soil damage are included. As well, the handbook offers ways to modify harvesting operations when soils have become susceptible to damage. Maintaining soil health during harvesting requires knowing when soils are at increased risk of compaction and rutting, and understanding how equipment operation interacts with the soil. If contractors, operators, and field supervisors can anticipate susceptible soil types and conditions, they will be able to plan ahead and make changes to their operating schedules and techniques. Recommendations made in this handbook regarding equipment and operating techniques are to serve as guidelines only. Local operating conditions and regulations, as well as equipment availability, must be considered when interpreting this information.