I have been riding dualsports on and off for years - they put on some great ones in Ohio and most get a large turnout. They normally are about 5 hours in the saddle with lunch in the middle. They can get a bit technical but since nobody is racing everyone is pretty laid back so you can always get help if needed. They normally loop you back to the start about half way so you can fuel up(need to have at least 40m in range on a tank) and they feed you lunch. I did some enduros but I am not crazy about waiting around at the beginning and then trying to catch up when you get behind. Plus riders get way more aggressive. The below link is a great resource and there are some good ones in OH-most south of you but Flint Ridge, Zanesville(ZTR), Nutcracker, Baby Burr are all really good. Be ready for some hill climbing - I rode an Enduro at the Athens Motorcycle Club once and had an altimeter with me - went up 10,500 feet and down 10,500 feet-that's nuts if you think about it. Finally - if you are looking to get your feet wet go to the Wayne National Forest-weekdays or EARLY on the weekends so you can avoid the crowds because the trails are 2 way and some fools just don't think on blind corners. I live 40m from the trailhead and about 20 times a year I would leave my house at 0530 on SAT or SUN, in full gear, get there around 630 and ride a 40m loop in the Wayne and be leaving when everyone was just getting started by 830. 120m loop and my bike was washed and in the garage by 10:00. I have done it less because of vintage mx and my trusty DRZ is around 15,000 miles and a bit clapped out. Try the Wayne and one of these dualsports you won't be disappointed.
Mike - is Jack working for the AMA?
http://www.usdualsports.com/