Some important resources for natural birth the greater DC area include:
Birth Options Alliance — a site with lists of practitioners and an active Yahoo group
Nova Natural Birth Network — a new community forum with articles
Nova Homebirth Community — Information about legal issues and providers, and a Yahoo group
And more resources to come!
A Baby Affair — September 15, 2014 in National Harbor, 11-2:30
DC Birth and Babies Fair (took place in April 2013 but has a great list of sponsors with links)