The Thunder Bay watershed (HUC 04070006) has a land area of approximately 3,600 square miles and is located in northwestern Ontario, Canada. The hydrology of the watershed is dominated by the Nipigon River, which is the largest river in the area. The Thunder Bay region receives a significant amount of snowfall each year, with an average of 120 inches per year, which contributes to a large snowpack. Surface water in the watershed is primarily composed of lakes and rivers, with Lake Nipigon being the largest and most prominent. The reservoir constituents include a variety of fish species, including lake trout, walleye, and whitefish. Interesting climatic trends in the area include decreasing snowfall and increasing temperatures over the past several decades. Additionally, the region is known for experiencing severe thunderstorms, with lightning strikes being a common occurrence.