FSH 5109.18 - WILDLAND FIRE PREVENTION HANDBOOK WO AMENDMENT 5109.18-99-1 EFFECTIVE 06/10/1999 CHAPTER 50 - WILDLAND FIRE PREVENTION ENFORCEMENT AND FIRE INVESTIGATION Contents 50.1 Authority 50.2 Objective 50.3 Policy 51 WILDLAND FIRE INVESTIGATION 51.1 Cause and Origin Determination 51.2 Human-Caused Fires 52 FIRE RESTRICTIONS AND CLOSURES 52.1 Fire Restriction Orders 52.2 Emergency Forest Area Closures 52.3 Posting