Unfortunately there isn't a way to bring in selected portions of "big systems" such as Michigan's - it's the whole thing or nothing. With ARC536 Pro you can pick and choose the sites and departments.
You have a couple of options depending on whether your scanner is subject to being elsewhere in your state or will always be used in one location.
If your scanner may be used elsewhere, I'd suggest a system of Department Quick Keys where your local site and departments are on one Department Quick Key and those "elsewhere" sites and departments are on a different Department Quick Key. Then, simply turn the "elsewhere" Department Quick Key off. You could also set the avoids, but unavoiding is a lot of button presses.
You could also set the Location Control to On for the Favorites List and let the scanner turn off the unnecessary sites and departments.
If your scanner will never ever be used elsewhere, you could simply use Sentinel to delete those undesired sites and departments.