Monument Rocks Arch, Gove County, Kansas
Photos by Robert Vreeland (left) and Jay Wilbur (right)
NABSQNO 14S-346765-4295545. Monument Rocks Arch is a fin natural arch eroded through a remnant outcrop of Niobrara chalk. It is located on private property about 24 miles south of Oakley, Kansas, in southwest Gove County. The land owner graciously allows the public to access this area. Please be respectful when visiting.
Monument Rocks, which is also known as the Chalk Pyramids, has been designated as a National Natural Landmark by the National Park Service. It was the first such designation by the NPS and is due to its historical significance as a landmark along the Butterfield Overland Stagecoach Line.
Because the chalk it penetrates is so soft, Monument Rock Arch is eroding rapidly. Note the difference in its appearance in the two photos above. The left photo was taken in September 1979, while the right photo was taken less than 10 years later in January 1989. In addition to the obvious loss of the secondary lintel, note how the base has lowered. Photos taken in 2002 show even more expansion of the opening.
Monument Rocks Arch was listed in the Vreeland catalog as number 23-48 with a reported span of 9 feet. There is another, smaller, fin natural arch a few yards to the north.