The Rahway River consists of four separate branches that converge in Rahway, from whence it flows as a single waterway to its mouth at the Arthur Kill. The longest, or West Branch, courses for 24 miles from Verona. The East Branch rises in West Orange/Montclair and joins the West Branch at Hobart Gap in Springfield forming the main stem of the river. The Nomahegan Brook and Black Brook enter soon thereafter. The original Rahway River Parkway was approximately seven miles. The brooks and main stem through Union, Westfield, Springfield, Cranford, Kenilworth, Winfield, Clark, and Rahway (where it is joined by the Robinsons Branch and the South Branch) The parkway comprises several county, municipal parks, and trails along the banks of the river. some of which are part of the East Coast Greenway. The river continues into Linden, Woodbridge and Carteret, which also have parks along it, which are part of the 21st century Rahway River Greenway Plan.