I live in Evansville.
Ed pretty much summed it up in his post.
Currently, any items needing a "proper" heat treating process are taken to the local tool & die shop a few blocks away from me. They do not do it themselves; they ship it out.
The only heat treating I have done myself thus far: I forged some scrapers and chisels out of old files in a charcoal forge, quenching with water and/or old motor oil.
This was before I learned more about the processes of heat treating, and the only reason it was done was to have those tools.
Considering how "primitive" my methods were, I feel these tools are better than almost anything I could have purchased!
Currently, I am in the process of building a couple of different gas forges; should be ready this coming spring.
I also have a "Big Knife Kiln" from Sugar Creek Industries, courtesy of my ex who was an art major and heavily involved with ceramics! Wiring for 220 for that kiln is also on the agenda this coming spring.
I'm especially interested in using the kiln for its capabilities on stainless.
When I'm up and running, I'm gonna have to play with everything a while simply to learn and get experience. When I feel comfortable doing it well, I'll give ya a holler.
Till then, unless we're set up to do it ourselves, we're pretty much stuck shipping it out.
If you want it done locally, it might not hurt to call various tool & die, or even machine shops to get some leads.
As big as Evansville is, I have only found one place locally that advertises heat treating:
General Stamping & Coatings (812)422-7769
I know nothing about this company, so do not know if they specialize in certain products or not. I also do not know if they actually do it or sub it out elsewhere, but it's a lead.
For now, you're probably going to have better luck going towards Louisville instead of Evansville simply due to the much larger population of businesses catering to industry. Also, don't overlook the obvious- check their yellow pages.
Good luck,
Robert