Are you wanting reference from where you live now or the Mt. Vernon area? I live down south of Carbondale and ride the Cedar Lake Trails and the Lake Kinkade trails near Murphysboro. But, I am fortunate enough that I have these fire road trails about 8 minutes from my house in Anna. There are two trails (Trail of Tears State Park) that are 6 & 4 miles respectively. They both require a significant climb, but each has a wonderful payoff of fast flow that follows a ridge line loop and the 6 miles has a 2.5 mile descent that requires much more brake than pedal.