Plate 143 is a context view from the north of Long Marston Viaduct (Bridge no 252). The viaduct is 108 yards long and 60ft high and was built between 1871 and 1874 from red sandstone quarried at Dufton Gill, two miles away. It has stone abutments, piers and parapets, brick arches and stone voussoirs. The five spans vary from 43ft to 45ft. The viaduct crosses Troutbeck, which also lends its name to an alternative title for the viaduct.