One of the advantages of driving on a trip (instead of flying for example) is the chance to see some interesting sites.
Here I'm standing in front of the Abandoned Amarillo Helium Plant. The plant was operated by the US Bureau of Mines and produced almost all of the world's helium from 1929 to 1943. The region surrounding the plant contains more than 95% of the world's known supply of helium. The helium exists (mixed with other gases trapped underground. This area is a heavy producer of natural gas (among others).
Oh, this is also a type of geocache called an Earthcache. Earthcaches focus on geologic and geomorphic features of a location. This one focuses on helium, a naturally occurring Earth gas.