The closest is American Bottom/Independence, Carlton, and McMinnville.
What's Zwickelmania, you ask? From the Oregon Brewers Guild:
2011 President’s Day weekend, dozens of Oregon breweries and brewpubs will open their doors to visitors for the state’s 3rd annual Zwickelmania. Zwickelmania, hosted by the Oregon Brewers Guild (OBG), is a free statewide event that offers visitors a chance to tour Oregon breweries, meet the brewers and sample their favorite beers.
When: Saturday, February 19th, 2011 from 11-4 pm
What: Oregon Brewers Guild Brewery Open House.
Salem-area brewers, where's the love? Where's the mania?