We have the Cardinal Greenway here in Indiana, looking to do the full ride of it in june-ish should be 10x miles to get a century ride in prior to the 162 miles. Never been on it, but am going to go on it on Saturday to ride with the pack of 3 that we have for the RAIN ride.
I don't ever plan on using a trainer. Went to a local dirt trail recently, lots of offshoots, almost ate it on an expert jump I shouldn't have jumped, but didn't, just scratched up my leg on my pedal. The Trek does alright on dirt, even if the tire is balding, which I need to replace very soon. If I continue on dirt, I plan on getting another bike, full suspension instead of just the hardtail Trek. There aren't many trails near me, we have one that is 6.2 miles round trip here in my City, it suffices for now, but look to goto a much longer trail soon, see above.