What is the only county in the USA to border 5 counties from 5 different states : Baca County, Colorado; Morton County, Kansas; Texas County, Oklahoma; Dallam County, Texas; Union County, New Mexico ?
Cimarron County It has all these odd relationships because it is at the end of the Oklahoma panhandle.
What is the dam in the Black Canyon of the Colorado River on the border between the US states of Arizona and Nevada that was completed in 1935?
The boundaries of four states of the USA, known as the Four Corners states, meet at one point, the only such geographic point in the USA. They are Colorado, New Mexico, Arizona and which other?