Cisco (Coregonus artedi) is Montana's newest fish species. They were introduced by the Montana Department of Fish, Wildlife and Parks into Fort Peck Reservoir in 1984, from Saskatchewan, to act as a forage fish for walleye and lake trout. They have produced a rapidly expanding self-reproducing population. Studies are ongoing to determine the value of cisco as a forage fish. Cisco, also known as lake herring, are widespread across eastern and central Canada. They spawn in the fall in shallow water. Cisco are an open water or pelagic species, forming large schools at medium depths where they feed mostly on plankton.