Mud, Rocks, Forest Service Roads, Dirt Trails that might have v-Ditch's or off camber areas, etc.
Rocks, heck yeah.
Dirt trails and V-Ditches, sure.
Off Camber, fun to a point.
Service Roads, occasionally sure, can be fun.
Mud - NO THANKS, been there done that got the t-shirt about 30 years ago.
What else? One of the things I miss about Michigan......Sand Dunes.