Uber has had an engineering presence in Seattle for at least four months: http://www.geekwire.com/2015/uber-opening-seattle-engineerin...

Not sure if it also include Seattle but it appears to include Boulder http://www.dailycamera.com/business/ci_28402965/uber-buys-bo...

I immediately thought it was Boulder when I read this, based on what I know of the Bing office here(Boulder). Seattle would make more sense if there's a mapping team AND Uber already there though.