Indiana Wild Trout
Indiana has extremely limited wild trout opportunities, though many folks feel that its salmon and steelhead runs in and out of Lake Michigan (dependent on stocking) are as good or better than any of its neighbors' programs.
Source: IN DNR, Title 327 IAC 2-1.5-5 Surface water use designations, US EPA Waters Database, Google Earth
The Indiana State Code calls out 6 streams (and their tributary systems) as "Salmonid Water", which are depicted in the image (the KMZ that generated this image in Google Earth is available by clicking on the >>Indiana Downloads link in the Midwestern Resources menu). However, the IN Department of Environmental Management classifies all of these streams as warmwater habitat.
Nevertheless, these are undoubtedly the highest quality Indiana streams that empty into Lake Michigan. They are also the streams which IN Division of Fish and Wildlife stocks with Coho and Chinook Salmon and both winter-run and summer-run steelhead. Fish are raised in hatcheries for a year, before being stocked in these streams prior to their migration to Lake Michigan. Much of emphasis of these programs is for off-shore fishing from boats in the lake, but opportunities for stream fishing certainly exist, especially for the steelhead runs.
According to email correspondence with the District 1 Fisheries Biologist, "there are a few locations in the headwaters that likely have limited natural reproduction, but it is very spotty." The only documented self-sustaining population is supported by a tributary of the East Branch of the Little Calumet. The fishery is located on private land and is currently not accessible to anglers.
The only other documented site is a brook trout stream in the NE corner of the state called Curtis Creek. This holds fish thought to have been stocked (the stream is listed in USWS stocking lists from the late 19th century). It is the water source for the Indiana state fish hatchery, and is closed to fishing. It too is marked in the KMZ, though not depicted in the image.
As the District 1 Fisheries Biologist wrote in his email: "Some of our put and take trout fisheries do have hold-over capabilities with the potential of natural reproduction but the extent is unknown." The put and take fisheries are the streams on the Indiana trout stocking list (36 in the 2013 list). If Indiana had a cool summer (or, even better, two cool summers in a row) it might be worth checking some of them out. My suggestion, if you're interested, woud be to correspond with the District biologist for the stream you're thinking of exploring prior to going out. Temperature is not the only factor affecting reproduction (silt and bottom structures are also important) so these individual streams may vary widely in their potential for natural reproduction. Contact information, including email addresses, for regional fisheries biologists is helpfully provided on the INDNR website.
Access information on the INDR website can be found here.