I have a couple of young grandsons living in Ankeny who I’d like to introduce to bobbers, worms and rock throwing. Does anyone have knowledge as to whether the parks-ponds would be a good introduction?
Having raised two sons who now are solid with fishing flies, I learned three things in fishing with youngsters: *Leave my gear at home, *Quit while they continue to want to fish, and *It is good to end with throwing rocks. . . .
You bet! Hawkeye Park has a lot of small sunfish, especially crappies, that your grandsons may enjoy catching. Rather than a worm, I’d recommend a really small jig of some sort. Like 1/64th oz crappie tube jig, with the rubber legs on the jig body shortened. Fish under a very small bobber. Lots of small rocks around the shoreline for throwing, too. 
Good luck!
Thanks, Dave. You are a big help!
If the water in the pond is high, the the rocks may be submerged…but kids with sandals on can get their feet wet and pick some up.