Starting at the Castle Valley Trailhead, head up Castle Valley Road
the same as you would for Hole in the Ground. Before reaching the Hole in the Ground Trail, there is a right turn after a rocky area on doubletrack. Stay on the doubletrack, crossing over the PCT and the Summit Trail. At 1.2 miles, the DLRT starts to your right. Soon after, the granite garden begins - it's one of the best sections of trail featuring great vistas of the Donner area. Continue making your way along the trail, though the views will compete for your attention.
At the 3-mile mark, you'll be at Summit Lake. From here, there is a faint trail around the lake and several cool perches for a snack break. Start on doubletrack at the lake and follow it up and over a small hill. Then head downhill toward Truckee for a steep descent. Keep an eye out for a short climb to the left, where the singletrack picks back up on an exposed hillside. You'll pop out on doubletrack again for a short climb, then you'll be back on trail on the right.
After crossing a bridge, you'll arrive at an intersection with Wendin Way Access Trail
. Left continues up to the ridge, and right takes you down to the trailhead. Once up a short climb, you are on the ridge and in Tahoe Donner area. From there, you can take DLRT on a fast route down to the "bench" or delve into the Donner trails, where the possibilities are endless. The DLRT also functions as a great out-and-back. Head back the way you came! It is ALL good...