Groundwater tracing used to delineate recharge areas for subterranean streams at Oregon Caves National Monument and Preserve

Karst is a landscape where the hydrology of surface water systems is intricately connected to groundwater systems through the development of conduits and solutional opening in soluble bedrock, such as limestone, marble, or dolomite. This connectivity can present challenges to preserving water quality and quantity for karst aquifers, as activities that occur in karst areas can often have a direct impact to groundwater quality. Agency personnel responsible for managing karst areas must understand the karst landscapes that drain to springs and caves to properly preserve groundwater quality. Oregon Caves National Monument and Preserve is in Josephine County, Oregon approximately 11 miles east of the community of Cave Junction. The Monument and Preserve protect 4,554 acres of conifer-dominated forests, meadows, streams, and multiple cave systems.

From 2021 to 2024, the U.S. Geological Survey along with personnel from Oregon Caves National Monument and Preserve conducted a dye tracing investigation seeking to delineate recharge areas for two karst systems, Oregon Caves and Cave Next Door. Additionally, the study sought to determine if there were any hydrologic connections between these two karst systems. A total of eight dye injections were conducted, delineating a recharge area for each of the two karst systems, confirming hydrologic connections among different streams within the Oregon Caves system, and identifying previously undocumented resurgences for the stream in Oregon Caves.

This data release contains shapefiles that relate to dye injection locations, monitoring sites, dye traces, and delineated recharge areas. All files were created in ArcGIS Pro and each shapefile contains associated attributes for the features contained within. Layer files are included with the datasets to match symbology found in figures in the accompanying report. All shapefiles and layer files were created and modified in ArcGIS software. For a full description of the methods to create these files, see Process Steps in "ORCA_Metdata.xml" metadata file.