From IA,,,Southwestern South Dakota,,,,Most of the PDs are on Tribal land and you have to be really careful since you are usually required to have a Tribal guide with you and they are notorious for leaving in the middle of the day and if you get caught without one present, you can get a hefty fine by the Tribal Courts...There are some south central state grass lands that are free, but expect a lot of company if you are going to be there after mid June...Almost as bad as going deer hunting the first weekend of season...
When I was living in MO, some of us got lucky and got access to three adjoining ranches in SE Colorado, the largest was 75,000 acres and the rancher rented us his spare bunkhouse for $25 a night per person...even had TV, kitchen and shower...Since it was 35 miles from the nearest town, we packed in a lot of groceries for the week...
The problem with Colorado is that any public land east of I-25 is restricted for shooting PDs, so you have to be on private land...