The Rochester and Pittsburgh Coal Company was incorporated as the Rochester and Pittsburgh Coal and Iron Company in 1881 in Indiana, PA, by the Adrian Iselin family, Swiss investment bankers from New York City. The company's first mines were located in Jefferson County, PA, in an area known as the Saw Mill Run Valley. These mines, including the Walston Mine which, by 1885, was using much of the coal it produced to make coke, boasted the longest string of coke ovens in the world. Five hundred employees worked in the ovens alone.