I had no access problems in the 20-30 four day trips I took to fish Iowa when we lived in the Midwest. But there was also no shortage of water that I would have liked to fish, but did not bother as fishing access to privately owned lands requires (or did require back then 2001-2015) written landowner permission to enter. But, to Joe's point, there is lots and lots of excellent wild trout water on public lands, under DNR easement or posted as open by cooperating landowners.
The access situation in Wisconsin is considerably better though. In addition to an abundance or either publicly owned or DNR lease/easement arrangements, Wisconsin is also a "wet foot" state where all stream beds regardless of how small are considered public. This basically means there is no stream in Wisconsin you cannot access/fish so long as you remain in the stream bed. Most folks don't push the envelope on this stuff out there though which is probably why the privilege still exists.