 It was named after the colonial governor John Wentworth (1792-1808).The valley is oriented north-south and is located in a glacial trough named the "Folly Gap" (originally spelled "Folleigh").The section framed by mountains measures approximately in length, from Folly Lake in the south to Wentworth Provincial Park in the north with the width of the valley floor varying from in the south to in the north.