My two boys (5/6) and I started backpacking in Manistee National Forest in Michigan, we've gone three times this summer.
Besides Hoosier National Forest are there any other decent backpacking trails here in Indiana?
Ferdinand State Forest has a few trails. About any state forest and fish/wildlife area probably has at least one. Not sure whether they allow back country camping or not.
Knobstone trail is a good one. With boys that young, I'd recommend section hiking the trail over several visits. It's around 60 miles in total and makes for some interesting overnight visits.
Morgan-Monroe State Park -Low Gap trail, I have hiked all the trails and we even did an overnight off one of the trails) the selected camp sights did retain water, so def need to check weather forecast if doing an overnighter.
Turkey Run
Versailles State Park
The Adventure Trail in the O’Bannon Woods, and the Knobstone are Indiana’s best multi-day trips. The Low Gap trail in Morgan Monroe state forest is good for an overnight though can be day hiked.
I did part of the Techumseh Trail, in and out, 2 night, and it was very pleasant with just enough water that year in September.
We did the Knobstone later that year, had to stash water (which our driver helped us with) and had a good time but man was it work. They don’t call it the little AT for nothing, you are buying and selling all day long, might only be 2 or 3 hundred feet, but it’s up and down all day.
This year should be great with all this late rain.
edit to add; We did 45 miles of Pictured Rocks a couple years ago, and while Indiana is a totally different vibe, it’s still nice. But Michigan is special, in part because of how close it is and how many off road/overland forests you can camp in.
There are two interconnecting loops on the Knobstone Trail that can be accessed from Delaney Creek Park ... the Delaney Creek loop and the Spurgeon Hollow loop. You can set up a base camp at the park and do the loops as a figure 8, two smaller loops, or 1 big outer loop.