You could easily do Big Bear (backside) to Stateline. My husband and Henge have done that. Fun bike trails & 4x4 trails down the backside of Big Bear, into Johnson Valley (lots of trails there) to the 40 Fwy near Newbury Springs and then head north of the 15 Fwy. Fun stuff!
Ok, I had to verify with Chris if they road over or under the 40 Fwy. He said under and a truck will fit. Once they got to Baker, they crossed the 15 Fwy there. He said a truck "no problem".