Published by the Bell System
Includes a schedule of long distance phone rates from Denver to other towns in Colorado
Approximate publish date 1943.

Notice the confusing rate reduction paragraph to the bottom right of the rate chart.
"Sunday and night rate reductions apply on all calls when the day station-to-station rate is more then 35 cents."
Sounds a lot like the cell phone billing plans of today. Like... Huh??

For interest, Arvada, Broomfield, Englewood, Golden Lakewood and Littleton, while officially separate cities, are now actually engulfed by metropolitan Denver.

The Bell Telephone Hour, aka The Telephone Hour, was a long-run concert series which began April 29, 1940 on NBC radio and was heard on NBC until June 30, 1958. Sponsored by Bell Telephone, it showcased the best in classical and Broadway music, reaching eight to nine million listeners each week. It continued on television from 1959 to 1968. Throughout the program's run on both radio and television, the studio orchestra on the program was conducted by Donald Voorhees

You can listen to some recordings of "The Telephone Hour" on MyOldRadio.com

High Resolution version of map below (4 megs)
1940's Map of Denver
The thick black lines represent street car lines, the dotted black lines are buss routs

High Resolution version of map below (3 megs)
1940's Map of Downtown Denver