Exposed by erosion, cannonball concretions jut from the side of a sedimentary
butte in the North Unit of Theodore Roosevelt National Park in North Dakota.
For more information about the park, please visit www.nps.gov/thro.
It Might Be Interesting to Know (technical details for the bored): This is a
five-exposure HDR (high dynamic range) image. With a tripod-mounted camera and the
lens aperture at a constant f16, exposure was varied between -2EV and +2EV. The
exposures were combined and tonemapped to produce a fuller range of shadow and
highlight detail than could otherwise have been achieved in the harsh midday sun.