Further west rises a range of rolling, purple mountains known as the Berkshires. Near the New York border, the Taconic and Hoosac Ranges cross into Massachusetts; however, in general, the area is known as The Berkshires. The region was populated by Native Americans until the 18th century when Scotch-Irish settlers arrived, after having found the fertile lowlands along the Connecticut River settled. On reaching the Berkshires, settlers found poor soil for farming, but discovered numerous fast-moving rivers for industry. Pittsfield and North Adams grew into small, albeit prosperous cities. A number of smaller mill towns exist along the Westfield and Housatonic Rivers, interspersed with wealthy vacation resort towns.