Table of data on water quality of Baker Lake near Mount Baker, Washington

On March 10, 1975, volcanic activity on Mount Baker increased dramatically in the form of new or greater emanations of heat, steam and other gases, and ash from a known fumarole field in Sherman Crater (fig. 1). The greater heat output from the crater increased subglacial melting and subsidence of ice in the center of the crater (Frank and others, 1975). Flow of acid-rich waters into Boulder Creek, which drains that part of Mount Baker, apparently increased also. Boulder Creek discharges into Baker Lake (fig. 1), which is a reservoir used primarily for power generation but also for recreation, sport fishery, and salmon migration. This apparent increase in acidity of Boulder Creek water has raised questions about possible detrimental effects on Baker Lake.