The trail from the Bowen Ranch to the hotsprings enters USFS land when you cross the road (3N59a). It is local custom for clothing optional hiking after you cross this road. As 3N59a is a popular open OHV route, you never know who may come along and be offended by a clothing optional hiker. If you choose to hike nude (common practice) from the Bowen Ranch parking lot, keep your shorts handy when in the area of the road that crosses the trail. Use common sense and keep it low key.
Highway 138 to Summit Valley Road to Hesperia is paved all of the way. The junction of 138 and Summit Valley Road is right by the Silverwood store. They also have fuel and other last minute supplies. If you continue down 138 to 173, there is a nice campground at the Mojave Forks. Another option is to hike in on the PCT near the dam. Link on the the Deep Creek Volunteers website for directions to the Bradford Ridge Trail.