Horsetail Fall gully (dry), El Capitan, Yosemite
The gully normally occupied by the Horsetail Fall waterfall on the spectacular granite monolith of El Capitan in Yosemite National Park. The year in which this photograph was taken (2004) was particularly dry and Yosemite had no waterfalls whatsoever - a very rare event!
El Capitan consists of a coarse-grained granite capped with a finer-grained granite. Sculpted by glaciers, notably during the Sherwin glaciation around a million years ago, the exposed, sheer cliff face is a magnet for climbers.
(One of a sequence of 3 images in this gallery. This is a high-resolution scan from a 35mm original in my pre-digital archive).