I was thinking the weekend of Halloween at the Colorado Railroad Museum:

http://www.coloradorailroadmuseum.org/special-events

From the website:

"Trick or Treat Train – Steam-Up Event
October 29 & 30
9:00 a.m. – 5:00 p.m.

The Railroad Halloween Town is a safe place to enjoy Halloween. Catch a ride behind the historic locomotive in vintage passenger cars hosted by conductors and engineers in full costume. The Trick or Treat Train departs every 30 minutes between 10:00 a.m. and 4:00 p.m.
Visit all the Town’s special stops to fill your treat bag and tickle your funny bones. Like a visit to our “not so spooky” haunted railcar or the Olde Railroaders silly graveyard.

And get a great picture of your costume as you pause for a photo in our Pumpkin Patch.
It’s full steam ahead for tricks, treats and trains. "

I plan to attend in my Renaissance Scots garb. I thought this might be a fun chance for a Colorado gatherin'. What does everyone else think?