Take Highway 14 from Los Angeles and drive 4 hours up to Bishop. From there continue on the highway 395 30 minutes up to just before the Mammoth Mountain Ski resort turn off. Hot creek area is just East of the Airport.
Roads are not always plowed in the winter and they close the gate to the hot springs themselves. Need a 4x4 with chains to get around, but you will be well rewarded for your efforts.
This is actually a March photo where the jet stream pulls storms across the Sierras into the upper Owens River valley area. We were looking at Hot Creek when a storm starting moving in and we moved out. This picture shows that the storms carve the snow due to the great winds and on the upper right you can see the wind blasting the hill. The scene is truly epic and one needs to be ready to wait out a spring blizzard if caught in one.