The Trail Canyon trailhead is located at 37 degrees 52.153' N; 118 degrees 18.375' W at an elevation of 8,862.' The trailhead area itself consists mainly of a small parking lot surrounded by much vegetation; there really isn't a campground to speak of.
We tried to navigate to the trailhead in the dark using my Garmin Rino 120 with data uploaded from MapSource's US Topo CD-Rom. We ended up detouring into an abandoned mine because the MapSource software that I based my waypoints on showed the road going through the mine area. We camped on a plateau in the mine area that served as a decent campsite, but only if you have decent sleeping pads, since the area is littered with sharp rocks. It's more open and out of the way than the trailhead itself, though. The coordinates for our campsite are 37 degrees 53.413' N; 118 degrees 15.087' W at an elevation of 7,916.' Hope this helps.