This is the official page of the Colorado Blues Jam Post... by far the most comprehensive & detailed listing of these events.
It's a BLUES thing, I do not include generic open mic's in the listings. The post is free, both to subscribers and venues, my way of givin' something back. Published once a month, sometimes less frequently, with an occasional Special Edition.
There is always some editorial content before the jam listings, my opinion only... not a reflection of the viewpoint of any other entity that may show up here on Harmonica Planet. There are a handful of reasonable guidelines for venues to follow (see below), but other than that there is no obligation.