US lakes & pondsUS lakes & pondsSurface area: The USGS National Hydrography Dataset outline (NHD Permanent ID 132168516).
The red circle marks Grassy Sprain Reservoir.
Towns and counties: U.S. Census Bureau boundaries overlaid on the USGS lake outline.
Official NYSDEC pages. Rules and fees change; check before you go.
Built only from the data on this page: official access lists, OpenStreetMap beaches and trails, campground listings, state and USGS invasive-species records. We don't rate crowds or water quality.
No public access sites are listed for this water in the NYSDEC boat launch sites (data.ny.gov) data.
Shoreline: USGS National Hydrography Dataset (NHD Waterbody, Permanent ID 132168516), public domain. State outline: U.S. Census Bureau TIGERweb. Points: NYSDEC boat launch sites (data.ny.gov). Dashed trails: © OpenStreetMap contributors (ODbL). Interactive map: Leaflet with © OpenStreetMap contributors. Not for navigation.
OpenStreetMap shows about 0.6 mi of public hiking and walking trail within about 100 m (330 ft) of the Grassy Sprain Reservoir shoreline, mostly along the north and west shores.
The dashed brown line on the lake map shows these trails. We include paths, footways and marked trails that OpenStreetMap doesn't mark as private, and leave out roads, sidewalks and snowmobile corridors. Mapped trails can still cross private land or close for the season, and not every trail is mapped, so follow posted signs.
Trails: © OpenStreetMap contributors, available under the Open Database License (ODbL). Map data as of Oct 9, 2026. Trail lengths count only the parts within about 100 m of the USGS NHD lake outline.
Live from the National Weather Service API for the lake's coordinates (40.9734, -73.8510). The nearest station may be several miles away. NWS forecast for Grassy Sprain Reservoir. No live water-temperature sensor is shown because we haven't found a public one for this lake.
Based on solunar theory, an estimate. Major periods (about 2 hours) center on when the moon is directly overhead or underfoot; minor periods (about 1 hour) center on moonrise and moonset. The 0–100 activity score rises during those periods and gets a boost near sunrise and sunset and around the new and full moon. Weather, water temperature and pressure often matter more. Sun and moon times are calculated in your browser from the lake's coordinates with standard astronomy formulas, shown in ET (America/New_York), and accurate to within a few minutes.
Grassy Sprain Reservoir covers about 149 acres in Greenburgh and Yonkers, New York (Westchester County).
Grassy Sprain Reservoir touches Greenburgh and Yonkers in Westchester County, New York.
Know Grassy Sprain Reservoir? Tell us about the launch, parking, where they're biting or anything a first-time visitor should know. Tips go privately to the LakeRipple editor; nothing is posted automatically. Helpful tips may be featured on this page (we'll use your first name only if you give one).
Straight-line distance between lake centers. All New York lakes & ponds · All waters in Greenburgh