This is one of the hot tubs in the vicinity of the main springs at Spencer Hot springs, Nevada. Spencer Hot springs is located about 12 miles east of Austin Nevada.
When I arrived at Spencer Hot Springs, I just headed to where I saw the RV's. Later at home I realized that I didn't even make it to the main springs at Spencers Hot Springs but just to this soaking tub to the north.
Talking to someone there I learned that it's a job cleaning out the tub and can take upwards to 8 hours to complete. Part of the problem is the high tempature of the water coming out of the valve (which can be completely shut off). I would guess that it is at least 150 degrees or hotter. After cleaning and refilling the tub, the water is left to cool down to around 100 which takes several hours...