Here an updated list of local comic/science-fiction/anime/etc. conventions in the Colorado area in 2018! In this update, I added two more conventions (one next weekend!)...
NOTE: This does not include gaming conventions. I thought about adding them, but decided against it, just because I'm unlikely to ever go.
IDEA ConJune 9
Denver Comic Con
June 15-17
Denver Zine Fest
June 24
Myth and Legends Con 6/Westercon 71
July 4-8
Estes Park Comic Con
July 13-15
CO Springs Comic and Toy Con
July 28
Supernatural Offical Convention
August 17-19
Fort Collins Comic Con
August 24-25
Colorado Springs Comic Con
August 24-26
DenFur
August 24-26
Nan Desu Kan 22
August 31-September 2
Gunbarrel Pop-Up Comic Con
October 6
Pikes Peak Comic Convention
October 6
MileHighCon 50
October 19-21
DakuCon
November 9-11
Rocky Mountain Con
November 10-11
ChromicCon
November 10
Denver Retro Con
November 18
Also, here a con that is probably going to return this year, but has not announced a date...
Koelbel Con
A cosplay photo to close out -- Magical Girl Mercy (from Overwatch) at Denver Comic Con 2017:

Tomorrow's wallpaper