The Local 20 mural is located on the ESC (Engineers and Scientists of California) Local 20, International Federation of Professional and Technical Engineers AFL-CIO & CLC building at 8th and Clay in Old Oakland. It was painted in November 2014 by the Community Rejuvenation Project, Desi Mundo, Pancho Peskador and Youth Spirit Artworks when Local 20 moved into the building.
The mural covers two top-to-bottom walls. It shows workers doing the work of Local 20 workers and "imagery associated with engineering and science: an eye test chart reading 'IFPTE Local Twenty,' an optometry phoropter, powerlines supported by metal towers, a surveyor, medical professionals doing lab work with microscopes, and an EPA worker testing environmental pollution levels in a hazmat suit." from the CRP blog about the project here.