The Upper Ribble catchment includes the source of the River Ribble at the confluence of Gayle Beck and Cam Beck near the famous viaduct at Ribblehead, in the shadow of the Yorkshire Dales three peaks in the National Park area above Horton-in-Ribblesdale. This area is lightly populated and the main use of land is for the rearing of sheep. As the Ribble flows through Ribblesdale and on towards Lancashire the land becomes more fertile allowing dairy farming on the pastureland. The principal towns include Settle in North Yorkshire, Barnoldswick and Clitheroe in Lancashire.