At the trailhead, there is an immediate left and right fork. The trail to the left is a winding XC style with fair amounts of pedalling, a few exposed tree roots and a couple of stumps that have been ramped up into jumps (to flat landings). Those stump jumps have easy lines around them.
The trail to the right traverses the contour of the hill before dropping down at an angle that doesn't require any pedalling. It is more-raw than the XC trail.
GETTING THERE: Entrance to all the Challenge Block trails is from the high point of Radio Hut Rd.
GETTING OUT: After the initial downhill there is a climb with a choice to veer right (Challenge Uphill) onto Radio Hut road and either into Boulderdash or back to the trail start. Or veer left to complete the Challenge trail which exits onto Pohaturoa Road.