Big Creek flows through both Boone and Polk Counties in Iowa before entering the Des Moines River system. This tributary connects to Big Creek Lake, a significant 814-acre impoundment in Polk County, and eventually flows toward Saylorville Lake. The creek's connection to these larger water bodies creates an interesting fishery dynamic, particularly at the Big Creek Spillway, a massive structure built by the U.S. Army Corps of Engineers to control lake levels and prevent game fish migration between Big Creek Lake and Saylorville Lake. The spillway area presents unique fishing opportunities despite challenging rocky terrain on both sides. A fish barrier system has been installed at the spillway to help retain stocked fish populations and improve overall fishery quality. The waterway supports diverse habitat including standing timber, laydowns, rock piles, brush piles, and aquatic vegetation, with depths in the lake portion reaching 51 feet.