There are a lot of co-working locations in Portland and I think the list continues to grow. There are all types from small startups, incubators, and hackerspaces. It has been a few years since I was involved in Portland's tech community but here are a few I can remember:
OTBC: http://www.otbc.org/
Nedspace: http://nedspace.com/
PIE: http://www.piepdx.com/
Portland Startup Incubator: http://www.pdx.edu/accelerator/
Collective Agency: http://collectiveagency.co/
Flux: http://fluxlab.io/
ADX: http://www.adxportland.com/
Silicon Florist is the premier blog on Portland's startup scene. http://siliconflorist.com/
Calagator is an aggregator for events: http://calagator.org/
Calagator also provides a list of venues: http://calagator.org/venues?all=1