Elysian Brewing Company is hosting their 3rd Annual Pumpkin Beer Festival this month. October 20th, Noon - 10:00pm at their Capitol Hill location and October 27, Noon - 10:00pm at Elysian Fields. I've attended the last two years and it is not to be missed.
Below is last years list of beers brewed by Elysian for the event:
Night Owl Pumpkin Ale
The Great Pumpkin
Dark 0′ the Moon Pumpkin Stout
Purple Pumpkineater Lavender Saison
Portergeist pumpkin porter
Steamy Hollow California Common Pumpkin Beer
Each year they also cask condition a portion of the Night Owl in a giant pumpkin. Here's a picture from last year's tapping.
They also feature Pumpkin beers from other guest breweries. If you are in the area either of these weekends and like Pumpkin beers, don't miss this event!