Chinese Wall, a 50 million year old basalt dike.

Close up photograph of the Chinese Wall, a 50 million year old basalt dike.

Enhanced close-up photograph of the the Chinese Wall, a 50 million year old basalt dike.

Weathered and enlarged joint in multiple debris flows (lahars).

Chimney Rock, a weathered joint along a plane of weakness in the Eocene-aged Wapiti Formation.

Unsorted deposits from multiple stages of Lahars, mud, and debris flows composing the rocks of Chimney Rock.

Lithified, unsorted conglomerate derived from major mass movements flowing out of ancestral volcanos to the north.

Unsorted Mud flow deposits.

Multiple episodes of deposition showing a reverse layering of deposits with the coarsest rock fractions above finer deposits, characteristic of a mud/debris flow.

Large boulder-sized deposits indicative of a massive, high energy mud flow.

An episode of sedimentary sandstone sandwiched between episodes of mud flows. The sandstone is well-sorted and suggests a more fluid, higher water content for the deposits.

Another example of a lithified conglomerate formed from a high energy depositional environment.

Talus cones at the base of cliffs on the south-side of Sylvan Pass due to frost wedging about eight miles west of the east entrance of Yellowstone National Park, Wyoming.

A near vertical dike weathered in the sandstone and conglomerate composed of volcanic deposits of the Langford Formation 47 to 46 million years ago.

Another episode of rain with a nice rainbow forming against a partially clearing backdrop, Chief Joseph Scenic Byway, Wyoming. .

A nice rainbow forming on the back side of a partially clearly sky.