It could very well have been a Verizon pay phone. They have phones in a
> lot of areas that are not served by them. In California, you can look
> outside Albersons Supermarkets, Savon, 7/11 and a lot more.
In the Denver area, which is Qwest territory with the major phone directory being their spinoff Dex, Verizon is the brand name on one of the secondary phone directories.