Am I to understand this has been done and is legal? ( with proper permits and through proper channels if there are any) This sounds interesting. There are many Red Tails around here and have watched them hunt in the wild. Around here they feed on everything. Mostly the same varmints I hunt. Water fowl, grouse, quail, squirrels and rabbits.

Your first stop will be the Oregon Fish and Game. All regulations about falconry are umbrella-ed by the USFWS but detailed by the states. If it's anything like California, you'll need to pass a written test, build a hawk-house (mews) and then live trap a young of the year redtail. Start your reading with a copy of The Falconer's Apprentice by William C. Oakes. It is specifically aimed at the beginner using learning to fly redtails. I've got a whole bibliography you can have on the subject once you really get into the reading. Just send me a PM. Many books on falconry go in and out of print. IMO your best source is www.abebooks.com, the used bookstore of the planet. Also you can try Alibris and Bookfinder. Find out who your local hawking club is and make friends. You'll need a Master to guide you through the first two years until you get your General license.
Good hunting, brother,