It happened on the northbound size just south of Exit 14B in Ramapo at about 5:30 a.m.
As of 8:30 a.m., one lane remains blocked, with stop-and-go delays to the toll plaza.
The trailer was reportedly carrying gravel and diesel.
State Police confirmed there was one fatality, but no further details were immediately released.
This is a developing story.
Check back to Daily Voice for updates.
Click here to follow Daily Voice Pound Ridge and receive free news updates.