There has been a surge of supercharger development around DC and the midatlantic generally. Right now there is a bigger concentration of SC investment than in Cal. (at least as shown by the supercharge.info cones. It looks like Tesla is noticing that the concentration of wealth and education in the DC area means a big potential market of buyers that will want to drive and supercharge in a 500 mile radius. 2015 Small Area Income and Poverty Estimates Census Bureau: 4 Richest Counties in U.S. Are Suburbs of D.C.