In the opening sequence of the series the caption reads "New Mexico Desert June 13, 1947" and there is a green Interstate Highway directional sign which reads "Roswell 35m 'Interstate 25 shield' Please drive carefully..." Roswell NM is located 125 miles to the east of US Interstate 25, and the U.S. Interstate Highway System was not even authorized by Congress until 1956. The first instance of any Green Directional Signage wasn't until the Late 1950s in Florida.