Cuivre Slough is a stream located in Missouri near the Mississippi River, situated primarily between Lincoln and St. Charles counties. It serves as part of the Cuivre Island Conservation Area, which encompasses 1,461 acres, with the majority being an island within Mississippi River navigation pool 26, between river miles 235 and 238. The slough provides important fish habitat and is connected to the broader Mississippi River ecosystem. It offers anglers opportunities to catch a variety of fish species in a relatively calm backwater environment compared to the main channel of the Mississippi River. Water levels and fishing conditions in Cuivre Slough are influenced by the Mississippi River stage, particularly affected by Lock and Dam 26R near Alton, Illinois.