Here are a couple of panoramas and photos that I took on my visit to Lassen Volcanic National Park in California. I have provided a little bit of background info courtesy of Wikipedia when available. Enjoy!

Lassen Volcanic National Park is a United States National Park in northeastern California. The dominant feature of the park is Lassen Peak; the largest plug dome volcano in the world and the southern-most volcano in the Cascade Range. Lassen Volcanic National Park started as two separate national monuments designated by President Theodore Roosevelt in 1907: Cinder Cone National Monument and Lassen Peak National Monument.

The source of heat for volcanism in the Lassen area is subduction off the Northern California coast of the Gorda Plate diving below the North American Plate. The area surrounding Lassen Peak is still active with boiling mud pots, stinking fumaroles, and churning hot springs. Lassen Volcanic National Park is one of the few areas in the world where all four types of volcano can be found (plug dome, shield, cinder cone, and strato).

More info here.
Lassen Peak From the TopTrail Up Lassen PeakLassen Peak From the TopLassen Peak From the TopLassen Peak From the TopLassen Peak From the TopLassen Peak Looking SouthView From Lassen PeakTrail Up Lassen PeakLake HelenLake Helen PanoramaLake Helen PanoramaSteam RoomLassen Peak From the TopBlue MirrorColored MudIt's Dry Out ThereBumpass Hell PanoramaMudpotFools Gold