I am up in the northern Illinois too and haven't had any issues hanging my hammocks at IL and WI parks.  When I don't have a second tree nearby I take one of my spare boards for leveling and rig it up.  2X8 that is probably 6 ft tall.    Plant one end in the ground and lean it away from the hammock a little.  Tie the hammock to the top then run a rope back to my bumper or any other stationary object to anchor it.  I used a sign post for the site 25 feet away the last time.  Then I run a rope out each side and stake it to keep it stationary.  I can send you a pic if you want.  It doesn't take long and it used all stuff I already had with.