I looked at the chart, and decided to make a very brief hop to the Warner Springs Gliderport, on the other side of Lake Henshaw. It was very easy: all I had to do was follow the San Luis Rey River through a small valley and then turn over the lake. But somehow I still got disoriented.

Even then, I was going towards the wrong shore. I looked at the GPS and the chart again, and turned further to the left, and finally I spotted runway lights in the distance. Thereafter I managed to land without incident.
Once again, the engine died after I set it to idle, but I was at only 2800 feet this time. I still haven't figured that out. And I forgot to squawk Mode C during the trip, even though I was just inside the Mode C veil. Oh well.
I considered another flight, but the sun was setting and I don't feel good about flying this aircraft through the mountains in the dark.