The Frisco Greenway Trail is a multi-use "rails to trails" project. However, toward the South end of the gravel "trail" past the bridge/creek (about 1 mile from trailhead) there is a network of fast, semi-technical singletrack I would estimate at probably 3 or 4 total miles (perhaps a local could clarify?). Lots of roots, small rocks with a few challenging climbs and fast descents. Trail is not marked at all can be a little confusing to navigate, though you are never very far from the main gravel "trail". Singletrack ends at another parking lot on North st. and N. Railroad Ave.
Heading North on "Main street" in Joplin (Hwy 43) take a right turn (East) onto "Zora" and continue for approx. a mile, then turn right again (South) onto "St. Louis". Trailhead and parking lot are on the left (East) a hundred yards or so down "St. Louis"
http://www.singletracks.com/item.php?c=1&i=3536