This is an undeveloped open space area criscrossed with trails, more doubletrack than singletrack. The hills aren't big, but they can be steep. There's a bunch of options, but most are doubletrack and the primary surface is deep soft gravel/sand. This is a "go out and explore" area as there is no real designated route. The area isn't that large and you can usually see some landmark, so you don't have to worry too much about getting lost.
From Central Ave SE, go right on Four Hills Road. Ignore the right turn on Stagecoach Rd and bear left as 4 Hills turns into Stagecoach Rd (in the other direction). Ignore the right on Stagecoach LN and then go right at the tee to stay on Stagecoach Rd. Follow it to then end and park.
http://www.singletracks.com/item.php?c=1&i=5126