Bryon Boyce said
There is some newish signs put up by the FS a few years ago. One is just before you start climbing up Mt. Lowe. The trail on Rhododendron Ridge from a little north of Mt. Lowe to past Hawk Mt. was once part of the PCT.  

We did notice that on our way up (wish we'd known about it earlier!). From that sign, its only about 3/4 of a mile to the lookout - and the trail was recently maintained. And you can park right off 4670. In fact, we hiked on 4670 to get back to our Jeep. That made for a much easier return hike.

Did not knw that had been part of the PCT. Very interesting!