Thanks for bringing this thread back, I never saw it before. I've been a few places in NWI, some resulting in bad experiences. What I've learned is stay out unless you have permission. This is not like out west where there's public lands open to wheeling.
I posted the Lat. and Long. of each, I think you can put them into google maps. I know it works to paste them into google earth. I also have a few pictures posted here: http://www.panoramio.com/user/5190244
The road in Schererville posted above. Theres some more trails around that area but I havent been there. I have seen some pics from where the guy that bought my cousin's 04 F250 buried it in mud in that area.
Trails Benz (or Bends? I'm not sure why but they always called it that) - Unincorporated Dyer - I grew up riding ATV's here 1993-2006. Never had any trouble with anybody. I havent been there since 2008 but google earth tells me it hasn't changed. This area used to have miles of trails in all directions. Good trails for trucks and ATV's. The west side of the lake where the houses are now had a nice MX track. This is the one place I would feel comfortable going back to.
Moon Trails (looks like a moon crater) - Michigan City. I was here once and didnt have any trouble, but I hear sometimes the cops make people leave. Not to mention it backs up to the prison. Nice open sandy trails and a big sand half-bowl toward the back.
Lowell - I had just installed my CAD elimination kit and went down the block in the unbuilt part of my subdivision to test out the 4x4. What I didnt know was that the developer was out picking up peoples trash that was illegally dumped, so he was already upset. Next thing I knew the cops showed up. I patiently explained my situation and was told to go home. The developer was even more upset that the cops let me go.
Burnham - I've been "wheeling" here but it was work related and I had permission.
Schererville, 77th and Cline - A friend of a friend had to abandon his 2wd truck here after getting stuck in winter. Two days later he came back to find his truck ripped to shreds. I'm guessing the land owner was not so happy and used his tractor or some type of construction equipment to demolish this truck. My friend went to check out the damage that night and ended up getting stuck on some frozen ruts. He tried to cross them at 90* but the rut width matched his wheelbase perfectly and he was laying frame across them. He called me and I had to go pull him out with my pickup at 11 PM. We couldnt dig because the ground was frozen and I couldnt pull straight because there were trees on both sides. Eventually had to shorten the strap so we were basically bumper to bumper and pull a full throttle jerk and he broke free. It was a scary couple hours wondering if the owner was gonna show up with a shotgun.
Cook County Forest Preserve - I've been there many times on ATV's and never had a problem. but I've heard of some people getting their rides towed by Forest Preserve Police. Trails are too tight for trucks and Jeeps anyways. Theres a pretty steep ravine along the creek. The trails follow the ravine the entire distance on the east side. There was a postal Jeep upside down in the bottom of the ravine that showed up around 98. The last time I was there around 03 it was still there but you could barely see it. I wish I had pics. I got stopped on my ATV by Lake County Sheriff coming home from there once. While crossing from farm field to farm field (not farm fields anymore), we didnt cross the road at a 90* angle, we had to take it at an angle because the trails didnt match up. He gave us tickets for that. Also got stopped heading there once by Dyer PD, he told me to go home.
(this is the exact location of the Jeep)
Merrillville - Broadmoor Country Club - We could wheel here from the time the golf course shut down until they started to redevelop. It was fun while it lasted and never had problems.
Gary - 12/20 and Ripley Street - I was there once. My uncle used to wheel there in the 80's while he worked at the steel mill. Some open dunes big enough for trucks but more trails ATV only. The ATV trails are really cool. Wooded sand dunes with 45+ degree bank S curves. Again, I've heard stories of police. See a pattern here?
Anybody have anything else?