Lake is the northern end of the longest railroad platform in America under State Street. This island platform for the two-track line stretches from this station south to Jackson. The original northern end of the longest rail platform in America the Washington/State Station, this station opened along with the rest of the State Street Subway on October 17, 1943. This station opened as a temporary stopping station when the Randolph-Washington Mezzanine was closed for renovations on June 2, 1996, the station became officially an independent station on November 18, 1997 to provide better farecard only (now Ventra Card) transfers with shorter walking distances to the State/Lake Station, and the stopping locations of trains at Washington was modified. The Washington Station was closed on October 23, 2006 to allow construction of the now abandoned Block 37 Superstation. Tile still says Washington around the staircase/escalators up to the southern Washington/Randolph mezzanine. The station has the modern skyline renovations with skyline designs, mosaics on the platform ceiling with Ls on them, and modern lighted signage, name signs and strip maps along the lower section of the platform ceiling.
The station has two mezzanines, one at the northern end of long platform, and a southern one towards the end of the stopping area for trains. The southern Randolph-Washington mezzanine contains turnstiles that lead to a staircase/escalator north on the platforms, followed by a platform elevator down a short mezzanine to the platform, and a combined staircase/escalator that leads to a high exit only turnstile. A passageway leads into the Block 37 Shopping Mall and an underground connection to the northern mezzanine of the Washington Station on the Blue Line. Exits from this mezzanine are up to each side of State Street between Washington and Randolph, with an up escalator (farther south) and staircase to the east side of the street, and the staircase (farthest south), followed by the street elevator and then an exit only up escalator to the west side of the State Street.
The northern Lake-Randolph mezzanine, for the free out of system transfer (that has existed since the subway opened in 1943) to the Loop has a single staircase/escalator up from the platform. This fare control area is narrower than the Washington-Randolph mezzanine. From here an escalator and staircase up to each side of State Street between Lake and Randolph, the layouts are mirror images with the escalator farther north on the west side of the street, and staircase farther north on the east side of the street
Photos 1-3 taken on 1 August, 2011, 3 & 4 on 3 August, 2011; 5-8: 17 February, 2018; 9-15: 10 June, 2018