According to BLM surface land records, almost all of Chino Canyon is part of the Mt. San Jac State Park. The part that isn't is all of Section 7, in which the Valley Station and the parking lots sit. The N/S dividing line between Section 7 (tram property) and Section 12 (State Park property) is about 2/3's of the way from the Valley Station to the water tank below Tower 1. Essentially the section line is where the turnaround is on the paved road to the water tank.
Certainly the tram folks can prohibit access across their property (ala DWA), but it's not clear if the State Park property has any access restrictions. Theoretically, unless there are unknown, unposted restrictions, one should legally be able to descend Chino Canyon as far as the Valley Station's water tank (if one were stupid enough). You could then sit there and stare at the tram's security folks, contemplating your next move.
Perhaps something >= the "Lost Guy Traverse" might be from Humber to the peak, then down the Skyline to Palm Springs. It's a greater distance and elevation differential (and legal!)
