Scientists and engineers from the U.S. Geological Survey (USGS) Earth Resources Observation and Science Center (EROS) Cal/Val Center of Excellence (ECCOE) collected in situ measurements using field spectrometers to support the validation of surface reflectance products derived from Earth observing remote sensing imagery. Data provided in this data release were collected during select Earth observing satellite overpasses during the months of March through November 2024 at the USGS EROS facility in Minnehaha County, South Dakota. Each field collection file includes the calculated surface reflectance of each wavelength collected using a dual field spectrometer methodology. The dual field spectrometer methodology allows for the calculated surface reflectance of each wavelength to be computed using one or both of the spectrometers. The use of the dual field spectrometers system reduces uncertainty in the field measurements by accounting for changes in solar irradiance. Both single and dual spectrometer calculated surface reflectance are included with this dataset. The differing methodologies of the calculated surface reflectance data are denoted as "Single Spectrometer" and "Dual Spectrometer". Field spectrometer data are provided as Comma Separated Values (CSV) files and GeoPackage files.