For a full review of the status of access and trail conditions in the San Jacinto mountains high country following the Cranston Fire, see the previous post from 31st July linked here. Revised information is as follows.
The wilderness of the Mount San Jacinto State Park reopened today, Thursday 2nd August. Currently access is via the Palm Springs Aerial Tramway, as other routes pass through US Forest Service land, which remains closed (at least thru today, see below). This arrangement is outlined in a message on the State Park website (linked here). Also the Idyllwild and Stone Creek developed campgrounds reopened on Tuesday 31st July.
Currently all trails in the USFS San Jacinto Ranger District remain closed. The U.S. Forest Service issued an official forest closure order on the evening of 27th July, details of which are available at this link. However, a revised order may be released as soon as tonight or tomorrow, Friday 3rd August. This will likely reopen many of the trails that were unaffected by the Cranston Fire (and hence provide full access to the State Park wilderness). This will presumably include Marion Mountain Trail, Seven Pines Trail, Fuller Ridge and Black Mountain at least.
Black Mountain fire lookout reopened yesterday, 1st August. I accompanied Florian Boyd in having the pleasure of going back into service for the first time post-fire. Access is initially for lookout volunteers only, but hopefully this popular area will reopen very soon for all.