The pass is the saddle between the valleys of the Maruia River to the northwest and the Lewis River to the southeast. The saddle is located close to the small spa of Maruia Springs.
The Lewis Pass is named after Henry Lewis who, together with Christopher Maling, was the first European to discover the pass, in April 1860 while working as a surveyor of the Nelson Provincial Survey Department. Before this time the pass was used by the Ngāi TahuMāori of Canterbury to transport Pounamu (greenstone) from the west coast.
The area around Lewis Pass is protected as a national reserve. There are a number of tramping routes in the Lewis Pass area, including the St James Walkway. The short Alpine Nature Walk loop walk around an alpine wetland and tarn can be accessed from a carpark near the saddle.