Good luck on your trip, @Ham !
Lots of streams to fish there, for sure. There are many I still haven't visited. Most are small enough that you don't wade them, although fishing from shore is often difficult due to the tall weeds and prevalence of invasive Wild Parsnip everywhere. That is nasty stuff...do NOT touch it. Wear long pants, socks and long-sleeve shirts.
What you catch really depends on which streams you go to. There are streams with naturally-reproducing browns, and some that are stocked with fingerlings as "put-and-grow". The IDNR doesn't stock adult brown trout anywhere...so the ones you catch are generally stream-raised, or stream-born. Perfect fins, great colors.
For Brook Trout (which we tried for, but didn't catch any this trip), some streams have native populations, some are stocked from native Iowa populations.
For Rainbows...they are generally all stocked, although some have certainly managed to breed in the streams. Its fun to catch some with perfect fins, and in places where they've never been stocked (stream-born or migrants from other streams).