Hiked from Wrightwood to upper fish fork with dog, the sign at upper fish fork appears to be broken. There are good campsites near the stream equipped with rock tables and fire pits if any one is interested. The water seems to be flowing good. The trail down to upper fish fork is not obvious from little fish fork. I guess the best way to describe it is follow the creek down from little fish fork until you reach a fork with a much healthier stream. From the fork, go a little ways down and cross the river to the east. Keep close to the river on your way down, until the trail goes around the mountainside, and switchbacks down into upper fish fork, at which point the destination becomes obvious.
The road down to lupine is still closed at the time of the hike (May 29). It may be open now, but i did do mt. baden powell the other day (June 19) and saw that the sign had indicated both Lupine and Cabin Flat closed.