145th Street-Harlem (St. Nicholas Ave between 145th and 147th Streets) opened 9/10/1932: This station has 2 levels, the upper level is where the A (See A Lefferts and A Rockaway)and C trains stop, and the lower level is where the Concourse B and D trains stop here. There are 2 full time mezzanines, one at 145th street (4 street stairs available, one for each corner), and the other at 147th street (2 street stairs). Each side has 3 stairs from mezzanine to the upper level, and 1 escalator from each mezzanine, directly down to the Uptown only side lower level (B/D) platform. There are no escalators from the Downtown side to upper level. Like many other IND stations when first opened, it had a full length mezzanine connecting both of today's mezzanines; this space is now used by the NYPD as a Transit Bureau District Office. Unknown to most people, there was also exits in the middle of the closed mezzanine, there actually is (what appears to be) an original 1932 IND sign on the Downtown, upper level side that sits overhead in the middle of the platform. To see this sign, you need to stand and face the north end it reads "exit to street". Outside of the station, on the street, a closed and slabbed over staircase still sits on the Northwest corner of 146th Street and St. Nicholas. The upper level is 4 tracks and 2 island platforms; however the lower level has 3 tracks and 2 island platforms. The Uptown platform on the lower level is wider than the Downtown platform, the possible IND plan was to make the Concourse line in the Bronx as 4 tracks, but plans were scaled back down to 3. The Concourse line opened a year later after the first IND line (1933). This station is where midday and evening B trains terminate on the middle track before returning back to Brooklyn. During AM and PM rush hours, the same middle track is used by D Concourse express trains in the peak direction traveled only (AM Southbound and PM Northbound). From this point down to 59th Street/Columbus Circle, there are 4 lines (A (See A Lefferts and A Rockaway) , B, C, D) running. From 145th the train enters a maze of complex switches, but is actually easier to figure things out when you ride area between these points a few times each way.
- Anthony Lofston 
