WMATA's 50th anniversary from the start of service, Part 2a | The Original Approved Metrorail System (1968-1970)

This is part of a series.

-- "Reprint with editing: Today WMATA Metrorail's 50th anniversary from the start of service | Part 1: many lessons can be found, if you look"
-- "WMATA's 50th anniversary from the start of service, Part 2a | The Original Approved Metrorail System (1968-1970)"
-- "WMATA's 50th anniversary from the start of service, Part 2b | Lessons learned: Proposed expansions and the Metrorail system we don't have"
-- "WMATA's 50th anniversary from the start of service, Part 3 | Stations"
-- "WMATA's 50th anniversary from the start of service, Part 4 | Buses"
-- "WMATA's 50th anniversary from the start of service | Part 5: Making a better transit network | Connecting heavy rail + light rail + railroad -- a concept for New York City 

Recently I acquired a copy of the February 1976 issue of "Metro Notes", a tabloid published by WMATA throughout the construction process.  The Approved Plan Map (1968-1970) shows the current system, with 11 potential extensions.  Three were constructed:  (1) two Blue Line stations from Addison Road to Largo; (2) one station from Rockville to Shady Grove on the Red Line; and (3) the Silver Line.  

Two infill stations were later added, NoMA on the Red Line ("Having Turned a Corner, Washington’s NoMa Is Coming Alive," New York Times) and Potomac Yards on the Blue/Yellow Line ("Metro's New Potomac Yard-VT Station Is Open. Here's What to Know," NBC).  

The Map is below and also on my Flickr feed.