There is no legal wheeling areas in close proximity of KC. The closest legal area is Kansas Rocks Recreation Park (kanrocks). Its a fee (daily/yearly, cash only) use park, managed by volunteer group, open weekends only, have occasionally events on closed park days, 3 level of trails, little under 200 acres, no camping, and there will be someone there at the registration cabin.
Tuttle Creek ORV is located outside Randolph, KS. Open 7 days, dawn to dusk, no fee, managed by Army Corp of Engineers. No level description of trails. No one there. No camping.
I also frequent Southern Missouri Off Road Ranch (smorr.net) and its a fantastic place to go as well. Its private ORV and open weekends. Its also cash only. Great camping facilities.
Then there is Disney, OK. Not much of a park, but access to the spillways of the lake and the rolling treed hills beyond them. Heard the public camping facilities are closed during winter this year.
Most ORVs will be on FB, have their own website, etc. Search for your local Jeep or offroad organized club as well. KC does have a KC Jeep club. FB has lots of 'groups' too. Many groups hold meet and greet dinners monthly.
The next big event for KanRocks is the Wheelin' for Toys, 12/14. Its sponsored by the Brushbeaters Jeep club. The club's website has complete description for preregistering, etc. Bring an unopened toy, get in for $7. Clubs and FB groups usually hold a competition to who brings in the most quantity and size of toys. The toys stay in the local area for the kids.
There is a lot of comraderie between jeep owners in the KC metro area. We do a lot together when we can. Come join us in the KCJp club, FB groups, etc.