The Michigan Department of Natural Resources page on Northern Pike says that they spawn in early spring and are found in the Great Lakes and connecting waters of the Lower Peninsula year-round and that:
Pike are popular quarry of ice fishermen. Though they are primarily pursued with tip ups, baited with live minnows or suckers, they can be taken with rod and reel, either jigging or fishing with bait. Pike are a prime target of spear fishermen as well, who often use decoys or suspend suckers below their shanties to lure pike within range in relatively shallow water.
Pike typically spawn in the weedy backwater marshes; low water levels on the Great Lakes in recent years have probably hampered their reproductive success. Still, the shallow weedy bays of the Great Lakes and connecting waters, such as Lake St. Clair and the Detroit River, the Portage Lake system of Lake Superior and the bays of Lakes Michigan and Huron, remain productive pike waters. winter pike fishing
Inland, the drowned river mouths along the Lake Michigan shoreline – such as Muskegon Lake, Portage Lake and Manistee Lake – are all noted pike waters. Some of the larger inland lakes and reservoirs, such as Michigamme and Houghton, have significant pike populations, though they can be found in many lakes and virtually all the larger rivers in the state.