Mt. Baldy - highest point in L.A. County at 10,064' - is currently closed due to the Bridge Fire which, as you'll see in a later post, I saw happen from the summit of Baldy.
While waiting for Baldy to reopen, here are pics from the rather steep Register Ridge trail. It gains about 2500' in about 1.2 miles. The trail starts just after the metal register you see on the Ski Hut trail, and then it ends on the Devil's Backbone trail just below Mt Harwood. So, after climbing up the steep part, you still have about 700' of gain to get the Baldy summit.
While it's steep, it wasn't loose when I did it; I never felt myself slipping backwards but I use poles. About midway there's a rock outcropping that I read is Class 3 but I didn't explore it. I haven't gone down it and I'm not sure I'd like to, but I probably will one of these days.