Start from the boat launch and follow the trail that runs behind the picnic pavilian southward along the lake. The trail will take you through some double track up and over the dam on the southern end. It then turns to singletrack on the southwestern part of the lake for a mile or so, This section is actually quite fun but not well maintained (only me as far as I know) then returns to some double track in a coniferous forest. When you pop out near the western boat launch, look north to see the entrance to the NW section of trail. This is a bit rolly and has some nice lookouts along the lake. The double track keeps heading north and eventually connects with Rawls rd. An option to complete a loop is to go right on Rawls, then Right again on Mcree, then Moore, which will lead you back to Salmon and the boat launch.
This trail was not designed to be a MTB trail but when you live out in the middle of NW TN, there isn't a whole lot around and so you have to make lemonade. The lake is really quite beautiful and there are lots of cranes and some other birds that frequent/live at the lake. The lake is quiet and quite large. Great for Kayaking and bbqs. The docks are wheelchair accessible.
I have seen both equestrians and four wheelers use the trail, but the use is infrequent as the trail is not well maintained. I stumbled upon it within the last month and have done some maintenance. TWRA runs it, but because it is focused on "family fishing" there is no indication of real trail maintenance. Happy trails.