From the turnoff to the Tub, continue down Whitmore Tubs Road, turn at the fourth right and follow it to the end. Welcome to Shepherd's Hot Spring. (37°40'0"N, 118°48'14"W) It's at about 7,000 feet elevation.
As you can also see, there's a valve on the pipe so you can adjust the temperature. Good hot spring etiquette says to turn it off when you leave so the water isn't too hot for the next visitors. It takes less time to heat the tub up than to cool it down. On is with the knob in line with the pipe, off is with the knob perpendicular to the pipe. Follow the pipe and it leads to the actual hot spring. I doubt many people would want to soak in it.
If camping were allowed, I'd rate Shepherd's a 5 out of five. Instead, it gets 4.75.