Sulpher Works is one of the most easily accessible hydrothermal areas in Mt Lassen National Park, one mile past the southwest visitor center on highway 89 in northern California.

You know you’re getting close because the air begins to smell like rotten eggs! Deep underground the water is heated by hot or molten rock. The water rises, to creat boiling pools, mud pots, and super heated steam vents.

The effect is one of stepping back in time, when the forces deep inside the earth sculpted the surface that we know today.

These photos were taken in Feburary 2020.