Introduction, Current Conditions, and Long-Range Outlooks Here in Yellowstone Country, winter snowpack and how this snowpack melts from late April through June play the most important roles in summer water supply for both fish and agriculture from early June through mid-September. June through mid-September temperatures and rainfall play a secondary role. Only after mid-September does … Continue reading Snowpack Report and Predictions for Summer Streamflow and Fishing Conditions – Mid-February Update