The climb up Powerline Trail is a doubletrack/fire road through the remnants of the trees left by the Bobcat Gulch fire. At some point during the climb most people have doubts on whether the effort will be worth it. Fear not, the view looking into Rocky Mountain National Park at the top will affirm that it has all been worth it.
Head west (toward the mountains) out of the parking lot. When you reach dirt turn right and ride till you hit the dirt road that should be labelled "Powerline Trail". Go west on Powerline Trail, it will get steep. Go past the sign warning you that the trail is uphill only (for bikes) and that there are "Hazardous sections ahead".
Once things begin to flatten out you'll reach a T in the trail with singletrack heading in both directions. Don't go right it is a hiking trail only. To the left is the beginning of Ginny Trail.