Sinks Canyon Lander, Wyoming

Sinks Canyon looking up from the Pogo Agie River around The Sinks west of Lander, Wyoming

Sinks Canyon exposes over 400-million years of geologic history. Originally formed by ice age glaciers the Middle Pogo Agie River is continuing the erosion process that has shaped Sinks Canyon low these millions of years.

The uppermost formation exposed in Sinks Canyon is Tensleep Sandstone. That massive, light colored, wall at the top is the Tensleep Sandstone.

The dark streaks on the face of the Tensleep Sandstone is "desert varnish" created by colonies of bacteria that create & concentrate oxides of iron and magnesium.

Below the Tensleep Sandstone is the softer Amsden Formation that is hard to make out because it is the grass and tree covered slope.

Below the Amsden Formation is the Madison Limestone which the Popo Agie River disappears into before emerging 1/4 mile down the canyon at The Rise.

Sinks Canyon near Lander, Wyoming

Sinks canyon near Lander, Wyoming

Sinks Canyon Road in Sinks Canyon near Lander, Wyoming.

Tensleep Sandstone wall of Sinks Canyon near Lander, Wyoming

View of Sinks Canyon wall comprised of hard Tensleep Sandstone on top and the softer Amsden Formation on the tree covered slope.

Note the dark colored desert varnish that appears to drip down the sides of this sandstone wall.

Tensleep Sandstone forming the caprock of Sinks Canyon near Lander, Wyoming

Take particular note of the dark colored desert varnish that appears to be dripping down the side of this sandstone cliff.

Climbing into Sinks Canyon near Lander, Wyoming

View of Sinks Canyon from Sinks Canyon Road out of Lander, Wyoming.

Tensleep Sandstone forming canyon wall of Sinks Canyon near Lander, Wyoming

The dark streaks and spots on this sandstone wall are desert varnish.