I'm talking counties like Sioux, obrien, clay, Cherokee. I've seen some pockets where I drive closer to the river and do find a block of timber, I've seen some groups that were high in #. I'm sure you know NW IA better than me, especially considering your name. But, around us, I can go 10 sections in any direction and I wouldn't hit one of those blocks of timber. There's 4 other farms in various locations I will go to that's the same thing. I scope it out all the time while I'm there trying to see if there's any decent pheasant spots. Absolutely there's some pockets but I have to go through at least 10+ miles before I even find one when I've looked, then past those, same thing again, pretty bare for anything. But, that's just my observation, nothing scientific of course.
But if you get in the Little Sioux River Valley, there are definitely areas that have large timber blocks, and within those, some densities that are very good. From my knowledge, Obrien, Clay, BV, Cherokee, etc. all have places where large blocks of timber hold a lot of deer. What we have noticed recently though, is those flatlander deer just aren't as abundant as they used to be. Seems like as our population has declined, those that remain gravitate to the heavy timber areas leaving nothing in the flats.