Big Cypress National Preserve – ORV Impacts on Vegetation

The CGR was asked by the National Park Service to assess the accuracy of off-road vehicle (ORV) trail maps and a corresponding digital database for Big Cypress National Preserve (BICY). These products were created in 1997-1998 from United States Geological Survey (USGS) National Aerial Photography Program (NAPP) color infrared aerial photographs recorded in 1994/1995 and resulted in the delineation of nearly 22,000 miles of rutted, undesignated trails.

Off-Road Vehicle (ORV) typical of those used in Big Cypress

ORV trails

ORV Trails - High Impact Area

For the accuracy assessment, areas corresponding to six USGS 7.5-minute quadrangles within BICY were selected for accuracy assessment. In May 2000, helicopter and GPS navigation system were employed to verify trail locations and classes noted on the maps. Nearly 1500 observed points were recorded from the helicopter or in the field. These points were input to the ESRI ArcView software package to color-code trail classifications and assess their accuracy with respect to the ORV trail maps.

ORV tracks dry season

ORV tracks - dry season

ORV tracks wet season

ORV tracks - wet season

Results of this study contributed to the development of an ORV management plan for Big Cypress. Download the final report.

ORV ground trail

Ground view of an ORV trail

ORV trail-Little Marsh

Sample ORV Trails map for the Little Marsh Quadrangle in Big Cypress National Preserve