A study was conducted from 2004 to 2007 by the U.S. Geological Survey in cooperation with the U.S. Fish and Wildlife Service to assess the characteristics of the local recharge areas of four caves in northern Arkansas and northeastern Oklahoma that provide habitat for a number of unique organisms. Characterization of the local recharge areas are important because the caves occur in a predominately karst system and because land use proximal to the caves, including areas suspected to lie within the local recharge areas, may include activities with potentially deleterious effects to cave water quality. An integrated approach was used to determine the hydrogeologic characteristics and the extent of the local recharge areas of Civil War Cave, January-Stansbury Cave, Nesbitt Spring Cave, and Wasson's Mud Cave. This approach incorporated methods of hydrology, structural geology, geomorphology, and geochemistry. Continuous water-level and water-temperature data were collected at each cave for various periods to determine recharge characteristics. Field investigations were conducted to determine surficial controls affecting the groundwater flow and connections of the groundwater system to land-surface processes in each study area. Qualitative groundwater tracing also was conducted at each cave to help define the local recharge areas. These independent methods of investigation provided multiple lines of evidence for effectively describing the behavior of these complex hydrologic systems. Civil War Cave is located near the city of Bentonville in Benton County, Arkansas, and provides habitat for the Ozark cavefish. Civil War Cave is developed entirely within the epikarst of the upper Boone Formation, and recharge to Civil War Cave occurs from the Boone Formation (Springfield Plateau aquifer). The daily mean discharge for the period of study was 0.59 cubic feet per second and ranged from 0.19 to 2.8 cubic feet per second. The mean water temperature for Civil War Cave was 14.0 degrees Celsius. The calculated recharge area for Civil War Cave ranged from 0.13 to 2.5 square miles using the water-balance equation to 3.80 square miles using a normalized base-flow method. Tracer tests indicated a portion of the water within Civil War Cave was from across a major topographic divide located to the southwest. January-Stansbury Cave is located in Delaware County in northeastern Oklahoma, and provides habitat for the Oklahoma cave crayfish and the Ozark cavefish. January-Stansbury Cave is developed in the St. Joe Limestone member of the Boone Formation. The daily mean discharge for the period of study was 1.0 cubic foot per second and ranged from 0.35 to 8.7 cubic feet per second. The mean water temperature for January-Stansbury Cave was 14.3 degrees. The calculated recharge area for January-Stansbury Cave using the water-balance equation ranged from approximately 0.04 to 0.83 square miles. Tracer tests generally showed water discharging from January-Stansbury Cave during high flow originates from within the topographic drainage area and from an area outside the topographic drainage area to the southwest. Nesbitt Spring Cave is located near the city of Mountain View in north-central Arkansas and provides habitat for the Hell Creek cave crayfish. Nesbitt Spring Cave is developed in the Plattin Limestone (Ozark aquifer) and is recharged through the Boone Formation (Springfield Plateau aquifer). The mean daily discharge for the period of study was 4.5 cubic feet per second and ranged from 0.39 to 70.7 cubic feet per second. The mean water temperature for Nesbitt Spring Cave was 14.2 degrees Celsius. The calculated recharge area for Nesbitt Spring Cave using the water-balance equation ranged from 0.49 square mile to 4.0 square miles. Tracer tests generally showed a portion of water discharging from Nesbitt Spring during high flow originates from outside the topographic drainage area. Wasson's Mud Cave is located near the city of Springtown