Most of Lake Ronkonkoma was built recently: 7% of its homes predate 1940 and the median home dates from 1970. Below: 3 old photos and papers, maps from 1902 on, and the census since 2000.
Every edition of the U.S. Geological Survey’s map of Lake Ronkonkoma. Tap a year, or press play to watch the town change.
1902Setauket sheet · 1:62,500
U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Lake Ronkonkoma.
The actual lake, Lake Ronkonkoma, adjacent to the CDP, is the largest lake on Long Island. The land surrounding one side of the lake is in the jurisdiction of the Town of Islip. The elevation of the lake surface is given as 55 feet (17 m) on the most recent USGS map, but as the lake is a "groundwater lake", not fed by streams, it has no surface outlet and its water surface reflects the current level of the local water table. This can undergo significant changes over time, and the lake level experiences slow periods of rise and fall. In the late 1960s it was quite low; after several intermediate changes in level, in 2007 the lake was higher than at any time since, with a difference of well over 5 feet (1.5 m) between the 1960s low and the 2007 high.
Passages that mention Lake Ronkonkoma, cut from the printed page as they were published.
...History of Suffolk county, New York1882 · page 48Read the page →
Read the text
Extending southward from the locality just mentioned to the borders of Lake Ronkonkoma lies a continuous settlement comprising about three hundred inhabitants, called Lake Grove. Lakeland, Lakeville and Ronkonkoma have been names applied to nearly the same locality. Several men from New York have made this locality their country residence. The beauty of the lake presents an attraction such as but few of the island villages
Text read by machine from the scan; it may contain errors.
Scans and text from the Internet Archive. Books published in 1930 or earlier, which are in the public domain.
Timeline
Lake Ronkonkoma, 1902 to 1971
Woven from the archive, old maps, post office records, the National Register and the people born here.
Nothing in the archives for these yearsWeddings on Main Street, storms, parades, school pictures, the old store. If it’s in your family album, it belongs here.
Founding dates: Wikidata, Wikipedia, the U.S. post office records of Blevins & Helbock (CC0) and the Census. Homes by year built: Census ACS 2020–24. National Register of Historic Places: National Park Service (list of May 22, 2026). Old photos, postcards and papers: Wikimedia Commons, the Library of Congress and other public archives, credited on each item’s page. Maps: U.S. Geological Survey historical topographic maps (via Esri) and Sanborn fire-insurance maps (Library of Congress). History text and census tables: Wikipedia (CC BY-SA 4.0). Places that used to be: USGS Geographic Names Information System (2021). How TownRatings grades history →
From Wikimedia Commons (3), the Library of Congress (3), Wikipedia, Wikidata and Wikipedia for famous people, U.S. Geological Survey historical maps, U.S. Census counts (via Wikipedia) and old county and town histories (Internet Archive). Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
1929
2010
2009
2009