Yellowstone River Basin study unit boundary, National Water-Quality Assessment Program, scale 1:100,000, Montana, North Dakota, and Wyoming

Release Date

2000-01-01

Time Period

1985

Publication Date

2023-09-15

Zelt, R.B. and Hallberg, L.L., 2000, Yellowstone River Basin study unit boundary, National Water-Quality Assessment Program, scale 1:100,000, Montana, North Dakota, and Wyoming: U.S. Geological Survey data release, https://doi.org/10.5066/P9KCX64I.

The U.S. Geological Survey (USGS) began full implementation of the National Water-Quality Assessment (NAWQA) program in 1991. The program objectives are to describe current water-quality conditions and trends over time; and to improve our understanding of the natural and human factors that affect water quality. The Yellowstone River Basin (YRB) is one of more than 50 areas to be studied for this program. Water-quality characteristics of the YRB are influenced by the environmental and geographic characteristics of the study unit. Efficient quantification of these study-unit characteristics requires a digital map of the study-unit boundary that may be processed, together with other digital thematic maps (such as geology or land use), in a geographic information system (GIS). The boundary of the YRB follows surface-drainage divides. The digital boundary data for the study unit were based chiefly on 1:100,000-scale (50 m accuracy) digital hypsography data.

• Model Data Management Function (MDMF)