While doing a bit of research on lumber companies in Bethesda, I came across the “who we are” page for ProMark Real Estate, whos predecessors included Einsinger Mill & Lumber Co, which occupied the space at Woodmont Ave & Bethesda Ave. This is the “lumber mill siding” we see so often in photos of the Bethesda yard. This is also the siding that was uncovered a few years back during excavation for the new apartment building. The family has a rich history of building in Montgomery County and the pages are worth a read! They were customers of the Georgetown Branch since the 1920s to the end. Really neat!