RESEARCH REPORT USDI, U.S. Geological Survey FORMAL AND INFORMAL TRAIL MONITORING PROTOCOLS AND BASELINE CONDITIONS: GREAT FALLS PARK AND POTOMAC GORGE Final Report Distributed by: Virginia Tech, College of Natural Resources Department of Forest Resources & Environmental Conservation U.S. Geological Survey, Virginia Tech Field Unit College of Natural Resources & Environment Department of Forest Resources & Environmental Conservation & Environmental Conservation Management FORMAL AND INFORMAL TRAIL MONITORING PROTOCOLS AND BASELINE CONDITIONS: GREAT FALLS PARK AND POTOMAC GORGE January 2011 by: Jeremy Wimpey Postdoctoral Research Associate Virginia Tech/Department of Forest Resources & Environmental Conservation Virginia Tech/FREC (0324) Blacksburg, VA 24061 Jeffrey L. Marion Unit Leader/Adjunct Professor Virginia Tech Field Unit USGS Patuxent Wildlife Research Center Virginia Tech/FREC (0324) Blacksburg, VA 24061 Final Report for the USDI, National Park Service Chesapeake & Ohio Canal National Historical Park George Washington Memorial Parkway TABLE OF CONTENTS TABLE OF CONTENTS ............................................................................................................................................ I FIGURES .................................................................................................................................................................. III TABLES .................................................................................................................................................................... III ACKNOWLEDGEMENTS ..................................................................................................................................... IV EXECUTIVE SUMMARY ...................................................................................................................................... IV INTRODUCTION ....................................................................................................................................................... 8 JUSTIFICATION FOR MONITORING ................................................................................................................ 10 LEGISLATIVE MANDATES ........................................................................................................................................ 10 Agency Organic Act ........................................................................................................................................... 10 Management Policies and Guidelines ................................................................................................................ 11 CARRYING CAPACITY DECISION-MAKING ............................................................................................................... 13 VISITOR PERCEPTIONS OF RESOURCE CONDITIONS ................................................................................................. 15 MONITORING PROGRAM CAPABILITIES ................................................................................................................... 16 LITERATURE REVIEW ......................................................................................................................................... 17 VISITATION-RELATED RESOURCE IMPACTS ............................................................................................................. 17 Formal Trail Impacts ......................................................................................................................................... 17 Informal Trail Impacts ....................................................................................................................................... 19 Trail Management .............................................................................................................................................. 20 INDICATORS AND SELECTION CRITERIA................................................................................................................... 21 Preferred Indicators ........................................................................................................................................... 23 TYPES OF TRAIL IMPACT ASSESSMENT SYSTEMS .................................................................................................... 24 Assessing Informal Trail Networks .................................................................................................................... 25 STUDY AREA ........................................................................................................................................................... 27 METHODS ................................................................................................................................................................. 30 TRAIL ASSESSMENT PROCEDURES ........................................................................................................................... 30 Formal Trails ..................................................................................................................................................... 30 Informal Trails ................................................................................................................................................... 33 RESULTS ................................................................................................................................................................... 35 GEORGE WASHINGTON MEMORIAL PARKWAY, GREAT FALLS PARK ...................................................................... 35 Formal Trails ..................................................................................................................................................... 35 Trail Design Indicators ...................................................................................................................................... 35 Trail Condition Indicators ................................................................................................................................. 38 C&O CANAL NATIONAL HISTORICAL PARK ............................................................................................................ 42 Formal Trails ..................................................................................................................................................... 42 Trail Design Indicators ...................................................................................................................................... 42 Trail Condition Indicators ................................................................................................................................. 43 GEORGE WASHINGTON MEMORIAL PARKWAY, GREAT FALLS PARK ...................................................................... 47 Informal Trails ................................................................................................................................................... 47 Quantitative Summary of Informal Trails: GFP ................................................................................................ 47 Spatial Distribution of Informal Trails: GFP .................................................................................................... 50 Fragmentation by Informal Trails: GFP ........................................................................................................... 53 Cliff-Associated Trails: GFP ............................................................................................................................. 55 C&O CANAL NATIONAL HISTORICAL PARK ............................................................................................................ 59 Informal Trails ................................................................................................................................................... 59 Quantitative Summary of Informal Trails: CHOH ............................................................................................. 59 Page i Spatial Distribution of Informal Trails: CHOH ................................................................................................. 62 Fragmentation by Informal Trails: CHOH ........................................................................................................ 66 DISCUSSION AND MANAGEMENT IMPLICATIONS ..................................................................................... 69 REVIEW AND SUMMARY OF FINDINGS ..................................................................................................................... 69 Management Suggestions ................................................................................................................................... 69 LITERATURE CITED ............................................................................................................................................. 74 APPENDIX 1: FORMAL TRAIL MONITORING MANUAL ............................................................................. 82 APPENDIX 2: INFORMAL TRAIL MONITORING MANUAL ........................................................................ 95 APPENDIX 3: GUIDANCE FOR MANAGING INFORMAL TRAILS ........................................................... 103 Page ii FIGURES FIGURE 1. THE NPS VISITOR EXPERIENCE AND RESOURCE PROTECTION FRAMEWORK USED TO ADDRESS CARRYING CAPACITY DECISION MAKING. ............................................................................................................................