1055 south of the hamlet of Dunningsville and McIllvaine Road southeast of the hamlet of Kammerer, in adjacent Nottingham Township, before reaching the borough limits of Bentleyville at the PA 917 interchange, which only contains an eastbound exit and westbound entrance. Shortly afterward, the expressway crosses over Norfolk Southern Railway's Ellsworth Secondary and meets modified right-in/right-out ramps to Wilson Road, which provides complete access to PA 917 and the center of Bentleyville to and from both directions. Following Bentleyville, I-70 enters Fallowfield Township, where it has a complete diamond interchange with PA 481, a westbound exit and eastbound entrance to Twin Bridges Road to the northeast of the hamlet of Lover, and a full cloverleaf interchange with the Mon–Fayette Expressway (PA 43), as the route descends into the valley of the Monongahela River. From here, the expressway curves east-northeast into the borough of Twilight, before crossing into the borough of Speers at the interchange with Maple Drive/Twilight Hollow Road. At this point, I-70 meets PA 88 at a pair of right-in/right-out ramps, prior to crossing over Norfolk Southern Railway's Mon Line, the Monongahela River, and CSX Transportation's Mon Subdivision on the Belle Vernon Bridge, where the route leaves both Speers and Washington County. Beyond the Belle Vernon Bridge, the route enters Westmoreland County within Rostraver Township. Here, it has a partial cloverleaf interchange with PA 906, before it crosses into the borough of North Belle Vernon and interchanges with Fayette Street, to the northeast of the borough center. From this point, the expressway heads back into Rostraver Township where it meets PA 201 at a partial cloverleaf interchange northeast of the community of Lynnwood-Pricedale that also provides access to PA 837. I-70 continues through wooded areas with nearby development, reaching an interchange with SR 3011 north of the hamlet of Arnold City in adjacent Washington Township, Fayette County, before coming to a cloverleaf interchange with PA 51 as the route begins to enter the valley of the Youghiogheny River. Past PA 51, the route crosses the Smithton High-Level Bridge over the Youghiogheny River and CSX Transportation's Keystone Subdivision, where it enters South Huntingdon Township. From here, I-70 interchanges with SR 3031 north of the borough of Smithton, PA 31 at cloverleaf to the northwest of the Pittsburgh Renaissance Festival grounds, and SR 3010 to the southeast of the unincorporated village of Yukon, before it comes into Sewickley Township. In this