The single-engine Piper PA-32 aircraft crashed after leaving nearby Greenwood Lake Airport around 2:30 p.m., the FAA reported.
The lone-occupant pilot wasn't immediately identified.
A full-scale response to the crash in state parkland off Airport Road included local police, firefighters and EMS, as well as the New Jersey Forest Fire Service, New Jersey State Police, the state DEP and Orange & Rockland Utilities.
Nearly 1,000 customers were without power after lines were downed.
The forest fire service sent ground vehicles as well as water-dropping helicopters.
The FAA and National Transportation Safety Board were conducting an investigation.
Click here to follow Daily Voice Mahwah-Ramsey and receive free news updates.