Spring Creek in Lewis and Clark County, Montana is a large, low-gradient, first-order spring creek that originates from the alluvial aquifer underlying the Lincoln Valley. This 5.3-mile waterway flows west entirely through private land, entering the town of Lincoln at mile 3.4 before splitting into two channels and eventually joining Keep Cool Creek. The creek exhibits the classic characteristics of Montana spring creeks - stable flows, consistent temperatures around 52 degrees year-round, and crystal-clear water that creates ideal conditions for both abundant aquatic insect life and selective trout behavior. Spring creek flows tend to seasonally rise and fall with the underlying aquifer and are influenced by an irrigation diversion off the Blackfoot River, with the upper portion becoming intermittent upstream of mile 4.5 from fall into early spring, while the lower portion maintains perennial flow downstream of mile 4.5.