The Michigan DNR page on rainbow trout (Oncorhynchus mykiss) explains that these delicious fish are native to the Pacific watershed, coming to Michigan when eggs were imported from California in 1876. They were first stocked in the Au Sable River, then four years later in Lake Michigan.
Now rainbows can now be found in everywhere, and the large specimens that inhabit the Great Lakes but travel inland to spawn in streams have come to be called steelhead.
You can generally fish for rainbow/steelhead from late April through September on Leelanau lakes & rivers including Lake Michigan, but be sure to confirm the details on fishing seasons in the 2019 Michigan Fishing Guide. Get your license too!!
Cortney caught this beautiful rainbow trout swimming in the Leland River in May of 2017. See more of her photos on Flickr!