NY 304 was assigned in 1930, originally following a series of at-grade roads that loosely parallel its modern alignment between Pearl River and Haverstraw.

Concerns over the route's ability to handle a projected 40,000 vehicles per day in 1980 led to the construction of new highways south of Nanuet and north of New City in the mid-1960s.

From its southern terminus at the state border to its interchange with Washington Ave about a half a mile up, it is also known as Pearl Street.

The route continues north, entering the hamlet of New City as the highway intersects CR 27 (Germonds Road).

[8][9] Street traffic forecasters for the Rockland County Planning Department predicted in 1960 that the section of the road between Pearl River and Nanuet would serve 30–40,000 vehicles per day in 1980.

[11][12] The bypass, which extended from Central Avenue in Pearl River to West Nyack Road in Nanuet,[10] handles about 23,000 cars per day as of 2008.

[1] The Pearl River–Nanuet bypass was part of a larger plan to build a freeway extending from Pearl River to Haverstraw at Hook Mountain State Park; however, the section of the route north of Nanuet was cancelled as the county's 1980 traffic volume projection for the Nanuet–Haverstraw corridor was not high enough to justify the construction of a new highway.