Pulky's Pool, or Hilltop Hot Spring (there's disagreement over the name) is easy to drive to, just off Benton Crossing Road (the one that junctions with US395 at the little green church). (37°39'49.4"N, 118°47'20.2"W) The thing is, the spring is about a quarter mile from the parking area.
See the white speck at the bottom of the low hill? That's the Rolling Steel Tent.
At least it's a nice path of gravel and wood planks.
I walked to the spring, then back to the van, where I got my camera. Then I walked back to the spring, then back to the van. A mile a day keeps... something away.
The concrete and stone tub is about six feet in diameter and two and a half feet deep. Unfortunately, the concrete is very slippery with algae. The tub needs to be drained and scrubbed.
As for temperature, it's delightfully hot, right at my threshold of tolerance. There are two pipes feeding the tank. One, running from a closer spring, is hot. The other, running from a spring a little farther away, is also hot. Turn the valve and you get a choice of hot or more hot. Can't beat that.
Overall, I give Pulky's Pool/Hilltop Hot Spring a 4.75 out of 5.