Prepared as part of the USGS National Water-Quality Assessment Program. Sharon B. Mathey, ed. National Water Information System User's Manual, Vol. 2, Chap. Point feature attribute values were inspected and found to be consistently coded as described in the Entity and Attribute Information. The use of these sampling stations by an ongoing study does imply that changes or updates are likely during the course of active field data collection activities.
Point features present.
The data set included in this release is not comprehensive with respect to surface-water stations sampled for water quality constituents in the Yellowstone River Basin. The actual difference in position between the sampling stations and their digitized locations is unknown. All spatial data included in this release. One retrieval of NWIS Site File records was made, from the Wyoming NWIS data base. Copies of records for Montana stations had been transferred earlier from the Montana NWIS data base by the Wyoming data-base manager.