Spotted Lanternfly inPutnam County, NYSPOTTED LANTERNFLY GUIDE
Putnam County is a Hudson Valley exurban county tucked between Westchester and Dutchess counties — confirmed for SLF in 2021 as populations spread north along the Metro-North Harlem Line from the heavily infested Westchester zone. The county's character is defined by rolling forested ridges, reservoirs, and a rapidly growing NYC commuter population drawn by affordable housing relative to lower Westchester. Cold Spring village on the Hudson River is the county's primary tourism hub, drawing visitors from established SLF zones throughout the metro area. Clarence Fahnestock State Park occupies a large forested swath of the county's interior and represents a priority ecological monitoring zone. The Putnam Trailway — a linear rail-trail corridor — and the I-684 commuter corridor are the primary SLF dispersal vectors driving active spread through the county.
Highest activity zones
SLF Hotspots in Putnam County, NY
Clarence Fahnestock State Park
Active zone
Metro-North Harlem Line corridor
Active zone
Putnam Trailway greenway
Active zone
Cold Spring village waterfront
Active zone
I-684 commuter corridor
Active zone
Primary SLF food source
Tree of Heaven in Putnam County, NY
Tree of Heaven is established along the Metro-North Harlem Line rail corridor and I-684 road margins through Putnam County, creating SLF dispersal pathways from the established Westchester County infestation zone northward into this exurban Hudson Valley landscape. The Putnam Trailway has Ailanthus colonization along its former rail right-of-way that extends SLF habitat through the county's interior. Cold Spring village waterfront margins and Clarence Fahnestock State Park access road edges are priority monitoring zones as SLF populations continue to spread through this commuter county with strong ecological sensitivity.
Identify Tree of Heaven →Local action resources
What To Do in Putnam County, NY
Report a Sighting
Every sighting in Putnam County, NY maps the invasion front. Report directly to New York State DEC.
Report Now →Squish on Sight
See a spotted lanternfly? Kill it immediately — it is legal and encouraged in all states. Learn the best kill methods.
Full Fight Guide →Map ToH in Your Block
Tree of Heaven removal cuts off SLF food supply. Add ToH sightings to the community map to guide removal efforts.
View Sighting Map →Statewide resources
Full NY State Guide
County-level data, quarantine zones, treatment guides, and agency resources for the entire state.
See the full NY guide →Community intelligence
Live Sighting Map
See where SLF has been spotted near you in Putnam County, NY. Add your own sighting to help map the front.
Open the Map →Free weekly fight briefing
Fight SLF in Putnam County, NY.
One email per week. Your zip code. Your threat level. Your action plan. Know exactly what to do this week in Putnam County, NY.