Study area boundary derived from 1:1,000,000-scale hydrographic areas and flow systems for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

This dataset contains the amalgamation of the hydrographic area (HA) boundaries and
polygons for the GBCAAS study area. The study area consists of 165 HAs based
on Great Basin HAs defined by the USGS in 1988 (Harrill and others, 1988; Buto, 2009).
This dataset does not contain the HA boundaries or geologic details included in the source
dataset. For that information, please see the metadata for the source dataset at
https://water.usgs.gov/GIS/metadata/usgswrd/XML/sir2010_5193_ha1000.xml
The study area boundary dataset is used by the Office of Groundwater, U.S. Geological
Survey, in its hyrogeological framework website.