Hurricane Sandy made U.S. landfall, coincident with astronomically high tides, near Atlantic City, New Jersey, on October 29, 2012. The storm, the largest on historical record in the Atlantic basin, affected an extensive area of the east coast of the United States. The highest waves and storm surge were focused along the heavily populated New York and New Jersey coasts. At the height of the storm, a record significant wave height of 9.6 meters (m) was recorded at the wave buoy offshore of Fire Island, New York (fig. 1, inset). During the storm, an overwash channel opened a breach in the location of Old Inlet, in the Otis Pike High Dunes Wilderness area. This breach is now referred to as the Wilderness Breach (fig. 1). Fire Island, New York is the site of a long term coastal morphologic change and processes project conducted by the U.S. Geological Survey (USGS). One of the objectives of the project was to understand the morphologic evolution of the barrier system on a variety of time scales (days - years - decades - centuries). In response to Hurricane Sandy, this effort continued with the intention of resolving storm impacts, post-storm beach response, and recovery. The day before Hurricane Sandy made landfall (October 28, 2012), a USGS field team conducted differential global positioning system (DGPS) surveys at Fire Island to quantify the pre-storm morphologic state of the beach and dunes. The area was re-surveyed after the storm, as soon as access to the island was possible. In order to fully capture the recovery of the barrier system, the USGS Hurricane Sandy Supplemental Fire Island Study was established to include collection in the weeks, months, and years following the storm. As part of the USGS Hurricane Sandy Supplemental Fire Island Study, the beach is monitored periodically to enable better understanding of post-Hurricane Sandy recovery. The alongshore state of the beach is recorded using a DGPS to collect data around the mean high water (MHW; 0.46 meters, North American Vertical Datum of 1988 [NAVD88]) to derive a shoreline, and the cross-shore response and recovery are measured along a series of 15 profiles. Monitoring continued in the weeks following Hurricane Sandy with additional monthly data collection through April 2013 and repeat surveys every 2-3 months thereafter until October 2014. Bi-annual surveys have been collected through September 2016. Beginning in October 2014 the USGS also began collecting shoreline data at the Wilderness Breach. See below for survey collection dates for all data types. For along shore shoreline data, the MHW shoreline (0.46 m [NAVD88]; Weber and others, 2005) is derived from the field data using an interpolation method that creates a series of equally-spaced cross-shore profiles between the two survey lines that flank the MHW contour. The foreshore slope is assumed to be uniform on each profile. Using this slope and the two surveyed positions on each cross-shore profile, a simple geometric calculation is done to find where each profile line intersects the MHW contour. This shapefile, FIIS_Shorelines_Oct2012_Oct2017.shp, consists of Fire Island, NY pre- and post-storm shoreline data collected from October 2012 to October 2017. This dataset contains 25 Mean High Water (MHW) shorelines for Fire Island, NY (A total of 23 full shorelines, where two shorelines were collected over multiple days). Prior to and following Hurricane Sandy in October 2012, continuous alongshore DGPS data were collected to assess the positional changes of the shoreline (MHW - 0.46 m NAVD88) and the upper portion of the beach. In the five years following Sandy, 24 surveys were conducted collecting data along shore-parallel tracks to capture the base of the dune, the mid-beach, and the upper and lower foreshore. The alongshore tracks extend from just west of Fire Island Lighthouse to the western flank of the storm-induced breach in the location of Old Inlet, in the Otis Pike High Dunes Wilderness area. Oct 28 2012 (MHW shoreline/Cross-shore data) Nov 01 2012 (MHW shoreline/Cross-shore data) Nov 04 2012 (Cross-shore data only) Dec 01 2012 (MHW shoreline/Cross-shore data) Dec 12 2012 (MHW shoreline/Cross-shore data) Jan 10 2013 (MHW shoreline/Cross-shore data) Feb 13 2013 (MHW shoreline/Cross-shore data) Mar 13 2013 (MHW shoreline/Cross-shore data) Apr 09 2013 (MHW shoreline/Cross-shore data) Jun 24 2013 (MHW shoreline/Cross-shore data) Sep 18 2013 (MHW shoreline/Cross-shore data) Dec 03 2013 (MHW shoreline/Cross-shore data) Jan 29 2014 (MHW shoreline/Cross-shore data) Jun 11 2014 (Cross-shore data only) Sep 09 2014 (MHW shoreline/Cross-shore data) Oct 07 2014 (Cross-shore data/Breach shoreline) Jan 21 2015 (MHW shoreline/Cross-shore data/Breach shoreline) Mar 19 2015 (MHW shoreline/Cross-shore data) May 16 2015 (MHW shoreline/Cross-shore data/Breach shoreline) Sep 28 2015 (MHW shoreline/Cross-shore data/Breach shoreline) Jan 21 2016 (MHW shoreline/Cross-shore data) Jan 25 2016 (MHW shoreline/Cross-shore data) Apr 06 2016 (Cross-shore data only) Apr 11 2016 (MHW shoreline/Cross-shore data/Breach shoreline) Jun 16 2016 (Cross-shore data only) Sep 27 2016 (MHW shoreline/Cross-shore data/Breach shoreline) Jan 24 2017 (MHW shoreline/Cross-shore data/Breach shoreline) May 23 2017 (MHW shoreline/Cross-shore data/Breach shoreline) Oct 17 2017 (MHW shoreline/Cross-shore data/Breach shoreline)