The Glacier Lakes Ecosystem Experiments Site (GLEES) was established to examine the effects of atmospheric deposition and climate change on alpine and subalpine ecosystems. The site contains East Glacier Lake (3282 m elevation) and West Glacier Lake (3276 m elevation), and their watersheds. These two small lakes are located 120m from each other at the alpine/subalpine transition. The lakes are similar in surface area, depth, and volume, but differ in watershed size, flow patterns of input, and water chemistry (Musselman 1994). Water chemistry has been monitored on these lakes periodically since 1987. Preliminary data indicate that they are subject to acidification (Reuss et al 1993, Reuss 1994).