The U.S. Geological Survey recently concluded a five-year water quality study (2001-2005) of the Yukon River, including its major tributaries, from its headwaters in British Columbia, Canada to Pilot Station, Alaska near its mouth and just above tidal influence. The focus of the study was to establish a water quality baseline providing an important frame of reference to assess changes in the basin that may result from permafrost melting and a warmer climate.

Long-term water-quality databases are essential to understanding the effects of climate change on river basins. The Yukon River Basin baseline water quality database has been extended from 5 to 7 years due to the efforts of the YRITWC-USGS collaboration. Consistencies in data populations between the USGS 5-year database and the YRITWC 2-year database indicate protocols and procedures made a successful transition. This reflects the success of the YRITWC- USGS sponsored water-quality training workshops for water technicians representing 18 Tribal Councils and First Nations throughout the Yukon River Basin. The cohesion of USGS and YRITWC data collected during the past 7 years will be discussed and graphically displayed.