Black Rock Hot Spring sets in the shadow of Black Rock Point. It was the first water hole for the immigrants who passed across the Black Rock Playa on the Applegate Trail. It hides in a marsh of Tollie Brush near an old shepard's wagon now deteriorating away.
The spring has two parts to it. The first is a deep and hot multi-colored pool bubbling up steam. The other part is a shallow pool relatively warm that people have actually walked across. A dock has been built extending out on the shallow pool area but it is not advisable to step off the dock if you do venture out.
The green marsh runs south to the Black Rock Playa creating a vast marsh bog you don't want to drive in - or walk in either. Black Rock Hot Spring is a nice rest stop before trekking out to other ventures in the area.