No, steelhead are not native to Lake Ontario. Steelhead are actually a migratory (anadromous) form of rainbow trout, which are native to the Pacific Coast of North America, ranging from Alaska down to California. They were first introduced to the Great Lakes, including Lake Ontario, in the late 19th and early 20th centuries to provide a robust sport fishery after native species like Atlantic Salmon had declined due to overfishing and habitat loss. Today, the "steelhead" found in Lake Ontario are maintained through a combination of intensive stocking programs by New York State and Ontario provincial authorities, as well as some limited natural reproduction in specific tributaries like the Salmon River. These fish have adapted to the Great Lakes environment by using the lake as their "ocean," growing large in the bait-rich open waters before migrating up freshwater rivers to spawn. While they are now a staple of the local ecosystem and a primary target for anglers, they remain an introduced species. Their presence is a testament to successful fisheries management, creating a world-class "Pacific-style" fishing experience in the heart of the northeastern United States and Canada.