Prior to the establishment of passenger service, the site of Great River station was occupied by a freight-only station built by the
South Side Railroad of Long Island (SSRRLI) known as
Youngsport station. The station opened in 1897, and the original station building burned down in 1943. Between that time, a sheltered-platform was added to the other side of the tracks. In 1945, a modernist station designed by architect
Antonin Raymond replaced it, but it was burned down in 2000. The third station with high-level platforms was built in the late 1990s. The original shelter, however was restored by the East Islip Historical Society, and remains within one of the parking lots along the eastbound platform.
Club House station East of Great River Station, the South Side Railroad built a private station called Club House station in 1869 to serve the
South Side Sportsmen's Club. This station was located between Mileposts 45 and 46 inside today's
Bayard Cutting Arboretum, and was among a number of privately owned stations along the SSRRLI, which were not so uncommon during the 19th Century. It was closed in 1897. ==Station layout==