Environmental impacts associated with the degradation of off-highway vehicle (OHV) trails have become a serious concern in many regions. Where OHV trails indiscriminately cross alpine areas, wetlands, steep slopes, and other areas with sensitive soil conditions, trails can become rutted, mucky, and eroded. Such areas are referred to as degraded trail segments. Degraded trails develop when trail use exceeds the trail's natural carrying capacity.

For land managers, degraded trails are a significant environmental problem because of their direct effects on vegetation, soils, and site hydrology. In addition, degraded trails may have indirect effects on wildlife, site esthetics, and other resource values. For trail users, degraded trails reduce the utility of trail systems and lead to a less enjoyable ride. Unfortunately, with increased use of backcountry resources by OHV enthusiasts and other trail users, the miles of degraded trails are increasing rapidly (figure 1).

Figure 1—A degraded trail in interior Alaska.
Heavy use has stripped surface vegetation and
exposed permafrost soils to accelerated melting,
resulting in muddy, rutted trail surfaces,
erosion, and deep muck holes.

This document provides land managers and trail users with an introduction to OHV trail degradation and outlines a framework for management responses. The information presented is based on work conducted by the author in southcentral and interior Alaska, but it also applies to degraded trails in other parts of the country. Some of the principles also apply to degraded foot, mountain bike, and horse trails. The document presents some fundamental concepts of soil and site characteristics, and the mechanics of trail degradation. It also offers inventory methods to document trail conditions and prepare stabilization "prescriptions." In addition, it outlines a number of management options including trail rerouting, seasonal and type-of-use restrictions, use-level restrictions, trail hardening, and trail closure.

The information provided in this report is intended to stimulate additional research and networking among trail managers, trail users, and the conservation community. Only through the cooperative efforts of a wide range of public and private trail advocates can the environmental and social conflicts associated with OHV use be resolved. We hope that future efforts will lead to the development of a widely applied set of best management practices for OHV trail management.

We have used English units of measure instead of Standard International (SI), or metric units, throughout this report. The products discussed in this report are manufactured using English measurements and most trail workers are accustomed to English rather than metric units of measure. Appendix D includes conversions from English measurements to metric.