Take Tri-Met to 5th Ave, City Hall or Portland Building stop.

http://www.portlandoregon.gov/water/bac

To assist with access to City programs, services and activities, the City of Portland will reasonably modify policies/procedures and provide auxiliary aids,/services to persons with disabilities. To request an ADA accommodation, please notify the City no less than five (5) business days prior to the date of the accommodation is needed. Call 503-823-7404, by TTY at 503-823-6868, or by the Oregon Relay Service at 1-800-735-2900.