Brian,
From the Field Guide to Reptiles and Amphibians of NJ:
p 21
Northern Brown (DeKay's) Snake (Storeria dekayi dekayi)
ID: 9'-20 3/4'. This is a small brown snake. A vertical dark bar a short distance behind the eye is a key identifying mark. Ground color is light to dark brown or gray, sometimes with a slightly yellowish or reddish tone. Two rows of small dark spots run lengthwise along the sides of the back; a lighter stripe runs down the middle of the back between the dots. The dots may be hard to see. The belly is light yellow, brown, or pink, bordered by small black dots at the sides. Young are darker, with a yellow band around the neck, similar to the Ringneck Snake. Scales are keeled, 15017 rows, anal plate is divided.
Where to find them: Prefers moist upland and lowland habitats; may be found in relatively unpolluted suburban areas. It hides under debris on the ground.
When to find them: Active April through October
Range: Entire state.
It is not listed as a species of concern (threatened or endangered).
Renee