Thirty years of sampling in the Wind River Range (WRR) of Western Wyoming has shown that alpine lakes are increasing in nitrogen content and slowly acidifying. In many regions of the American West, atmospheric deposition of ammonium from fertilizers and nitrous oxides from combustion drive these changes. I hypothesize that in the WRR, deposition accumulates in the snowpack through the winter and then is rapidly released in early summer when the snow melts. This study focused on Deep Lake, a 60.5 acre headwaters lake at 3,218m in the Bridger Wilderness area, where lake chemistry samples have been collected annually as part of the National Atmospheric Deposition Program (NADP) and Interagency Monitoring of Protected Visual Environments (IMPROVE) since 1984. These data suggested that the WRR ecosystem is at critical threshold of transitioning from nitrogen limited to nitrogen saturated. We collected 101 water samples from the inlet, outlet and mid-lake in May and June during peak snowmelt and in August when the basin was snow free. Samples were analyzed for concentrations of Ca2+, K+, Mg2+, Na+, NH4+, NO3-, Cl-, SO42-, total Nitrogen, total Phosphorus and Gran Acid Neutralizing Capacity (ANC). Preliminary results show that that pH levels are lower and nitrogen content higher during snowmelt than when the watershed is snow free. Samples taken from the inlet of the lake are higher in nutrient content than samples from the lake outlet, which have been diluted by lake water. This indicates that atmospheric pollution is stored in the snowpack, and flushed through the system with snowmelt. Shifting nutrient levels in alpine watersheds are potentially deleterious to fragile ecosystems and can degrade water quality for downstream users. With over 70% of water in the American west coming from snowpack, it is highly important to understand the factors influencing snowmelt water quality.