Big Spring Creek Professional Review and Guide
"Considered to be one of the few significant trout streams in Central Montana, Big Spring Creek is the third largest freshwater spring in the world and bubbles to the earth’s surface in the foothills between the Judith and Big Snowy Mountains. The cold water is quickly absorbed back into the porous strata and reemerges again at Big Spring flowing at over 50,000 gallons per minute. Once a sacred site to Native Americans, and later a valuable resource to early settlers, Big Spring Creek is still a prized water source.
According to the EPA, Big Spring has been rated one of the purest springs in the U.S., and it is pumped directly into the homes of Lewistown residents without any purification. Big Spring water is also bottled and shipped across the country under a variety of labels. Types of Fish: Rainbow and Brown Trout, Whitefish. This fly-fishing chapter describes the "where, when, and how" for fishing in this area. It includes a full-page map and information on the known hatches, suggested equipment to use, the best flies to use, season, limits, nearby accommodations, and camping."