This is a fun thread.
I live in the Portland, OR area now and agree that we see a mix of artsy-hipster-thrifty-Etsy and outdoorsy gear (yet that often with a stylish edge) here, plus a little of everything else maybe? Rabbit's description "creative casual" is pretty perfect. And, it's great that if you do get creative, I think people appreciate it (as opposed to either ignoring it or judging it as other places might), yet if you don't, it's also not a problem at all. It's so accepting, and I find that freeing. We all know that some places seem to strongly encourage trendy/dressy style, but some others seem to enforce "casual or else." And if you have to dress down or be looked at funny, it's just as annoying as when you have to dress up when you don't want to!
Adding that as someone who lived in Boston for 20 years (and traveled there all my life, as my mom's side of the family is from there) and who was in high school (Princeton, NJ) during the true preppy heyday, I also never really saw Boston as *all* that preppy. I'd probably label the look people might be talking about as classic. To me, preppy is a bit more extreme. Pink and green, madras plaid shorts, boat shoes (Sperry Topsiders or Sebago Docksides, take your pick--always without socks), duck boots, penny loafers, Bass nubuck oxfords, scratchy wool cardigans with grosgrain ribbon backing on the button bands, plaid pleated mini kilt-style skirts, Nantucket basket handbags...and on and on. But I could be wrong. Maybe, like trix, I was a fish who didn't see the water I was in?