5280 magazine had a sidebar on coworking facilities in Denver/ Boulder this past month. They highlighted 4 firms:
Denver Coworking at the Hive, Creative Farm, ID345 Space
The Hive Cooperative - at $199 per month located at 2401 15th street in Denver.
The Creative Farm - between $300 and $700 per month, located at 4900 W. 29th Ave.
ID345 SPACE - between $250 and $750 per month is located in North Downtown at 2936 Larimeter Street.