Chimney Rock is a geological rock formation in western Nebraska's panhandle region. The image of Chimney Rock has been used on souvenirs, on the Nebraska license plate in the 1990s, and most recently on the 2006 Nebraska state quarter. It has been described as looking like a haystack with a pole sticking out of it or an upside down funnel.
Chimney Rock was designated a National Historic Site on Aug. 9, 1956. It was the most noteworthy landmark on the Oregon Trail for settlers and pioneers heading west in the 19th century. Those early travelers called it chimney rock because of the resemblance. Native Americans in the area had another name for it. They called it Elk Penis. They probably didn't know about chimneys.
The estimated height of the monolith has varied over the years from different sources. It is thought to have been as high as 500 feet millions of years ago. Today it is about 350 feet high from the base to the very top with the "chimney" about 120 feet of that total. It may decrease over time since it appears to continue eroding. The rock consists of clay, sandstone, and volcanic ash to which thousands of visitors have carved their names.