Fun little ride. My suggestions:
Park at the post office in Jamestown (not really any parking on Ward St. itself and the locals aren't fans of cars turning around on the dead end all the time). Ride past the houses on Ward St. and thru the gate. Nice couple miles along the river, you will cross the river and ride up a short hill to another gate. You then have a fork/choice. Go left and its pretty rocky, kinda tech but this time of year it shoudn't be wet so most if not all is rideable. Go right, grunt up the hill as well but its been graded so its just a hill climb.
Once at the top if you stay left (rd 331 I believe) you can ride back down to the other side of Jamestown but most of the downhill is open to 4wd so its pretty rutted and well, you may run into 4wds.
At the top there are also multiple little spur trails and loops, just be aware of potential horseback riders from that little resort outside of Ward (Gold Lake I think), not really well labeled but fairly obvious.
There is also some single track that will take you back down to the first Y, again, not signed but on your left as you ride along 331. Otherwise head back down the way you came after exploring the top, its quite fun as an out and back as well.
TrailCentral does a little write up and reviews:
http://www.trailcentral.com/trail/tr...o.php?trail=15, but their directions are to take the 331 back down which is the 4wd route.
Sorry this is a little vague but its kind of a vague trail, I haven't gotten lost up there yet and have done quite a bit of exploring, so have fun! You probably wont run into anyone, or very few. I rarely see anyone up there.