Here is a track I made a long time ago, of one of the legs on the Wolf River/Shelby Farms trail in Germantown, TN
I just bought Street Atlas 2005 today and WOW what a difference it makes over the program that came with my Garmin GPS.
The trail is the black line, and its 3.89 miles long from entrance to exit of that leg of the trail.
and for something to compare it too, here is MAPSource.
*top screenshot is from my desktop and bottom is from my laptop*