U.S. Route 301 in Maryland

View north along US 301 just after crossing the Nice Bridge

US 301 enters Maryland at the Virginia state line on the right bank of the Potomac River near Dahlgren in King George County, Virginia, from which the U.S. Highway continues toward Bowling Green and Richmond. The highway crosses the Potomac River on the Governor Harry W. Nice Memorial Bridge, a four-lane divided bridge. US 301 becomes a four-lane divided highway named Robert Crain Highway just east of the southbound-only all-electronic toll gantry for the bridge and to the north of the Morgantown Generating Station. The highway parallels CSX's Popes Creek Subdivision rail line on a sweeping curve from east to north through the community of Newburg. US 301 passes a welcome center and has a directional crossover intersection with MD 257 (Rock Point Road). The highway curves northwest at its directional crossover intersection with MD 234 (Budds Creek Road) at the hamlet of Glasva, then curves north again between Faulkner and Bel Alton, from which Chapel Point Road leads west to Chapel Point State Park.[1][7]

US 301 passes through the hamlet of Spring Hill shortly before it enters the town of La Plata, the county seat of Charles County. The highway passes to the west of the center of town and intersects MD 6, which heads east as Charles Street and west as Port Tobacco Road, and MD 225 (Hawthorne Road). US 301 leaves La Plata at Rosewick Road and gradually curves northeast toward White Plains. There, the highway meets the eastern end of MD 227 (Marshall Corner Road), passes near the eastern end of the Indian Head Rail Trail, and intersects Billingsley Road, which leads to the southern end of MD 925 (Old Washington Road). US 301 expands to six lanes near Smallwood Drive, where it passes south of a park and ride lot serving MTA Maryland commuter buses. The highway runs through the planned community of St. Charles, which contains the St. Charles Towne Center shopping mall. The highway continues through the unincorporated town of Waldorf, where the highway meets the eastern end of MD 228 (Berry Road) and the northern end of MD 5 Business (Leonardtown Road).[1][7]

US 301 northbound past MD 382 in Croom

At the north end of Waldorf, US 301 has a partial intersection with MD 5 (Mattawoman Beantown Road); access from northbound MD 5 to southbound US 301 is via Mattawoman Drive. The two highways curve north and cross Mattawoman Creek into Prince George's County. The highway temporarily gains extra lanes while passing through the area north of the county line, during which the highways cross Timothy Branch. US 301 and MD 5 diverge at a partial interchange in Brandywine, from which MD 5 continues north along Branch Avenue toward Washington and US 301 drops to four lanes. US 301 curves northeast and intersects Brandywine Road, which heads east through the center of Brandywine as MD 381. Brandywine Road to the west provides access from southbound US 301 to northbound MD 5 and from southbound MD 5 to northbound US 301. US 301 heads through the communities of Cheltenham and Rosaryville, where the highway passes along the east side of Rosaryville State Park. The highway continues through Marlton, where it crosses Charles Branch and meets the northern end of MD 382 (Croom Road).[1][7]

Old Crain Highway splits north from US 301 as the highway approaches Upper Marlboro, the county seat of Prince George's County. The U.S. Highway curves north and crosses CSX's Popes Creek Subdivision rail line at-grade and heads across the Western Branch of the Patuxent River south of its cloverleaf interchange with MD 4 (Stephanie Roper Highway). US 301 meets the eastern end of MD 725 (Marlboro Pike) east of Upper Marlboro. The highway continues north, passing a pair of weigh stations, and gains a wide median at the southern edge of the city of Bowie. There, the U.S. Highway intersects Old Central Avenue, which is part of MD 978, and has a six-ramp interchange with MD 214 (Central Avenue). The movements from northbound US 301 to eastbound MD 214 and from eastbound MD 214 to southbound US 301 are made via Old Central Avenue (unsigned MD 978B). US 301 follows the eastern city limit of Bowie and expands to six lanes south of its intersection with MD 197 (Collington Road). Past this junction, the road intersects Ball Park Road, which leads east to Prince George's Stadium, the home ballpark of the Bowie Baysox baseball team. The U.S. Highway briefly fully enters the city of Bowie just south of its cloverleaf interchange with US 50 (John Hanson Highway) and MD 3, which heads north along Robert Crain Highway while US 301 heads east concurrent with US 50 and unsigned I-595.[1][7]

US 50 westbound/US 301 southbound at the MD 665 exit in Parole

US 301 and US 50 head east along John Hanson Highway, a six-lane freeway, across the Patuxent River into Anne Arundel County. The highways have junctions with MD 424 north of Davidsonville and the southern end of I-97 in Parole. US 301 and US 50 pass to the north of Annapolis, which is accessed by interchanges with MD 665, MD 450, MD 2, and MD 70. The I-595 designation ends at the MD 70 interchange. MD 2 joins the U.S. Highways along the freeway to cross the Severn River. MD 2 splits north from the U.S. Highways at a common interchange with the eastern end of MD 450, where the freeway's name changes to Blue Star Memorial Highway. US 301 and US 50 meet MD 179 near Cape St. Claire and pass by Sandy Point State Park right before the highways use the dual-span Chesapeake Bay Bridge to cross the Chesapeake Bay. US 301 and US 50 meet MD 8 on Kent Island in Queen Anne's County. The six-lane freeway parallels MD 18 and has numerous right-in/right-out interchange with local roads as it passes through Stevensville and Chester. US 301 and US 50 parallel MD 18 across the Kent Narrows onto the mainland of the Delmarva Peninsula, then the freeway continues through more right-in/right-out interchanges in Grasonville before the U.S. Highways diverge at Queenstown.[1][7]

US 301 reduces to a four-lane non-freeway divided highway with a speed limit of 55 miles per hour (89 km/h) at its partial interchange with US 50 (Ocean Gateway). The highway passes along the edge of the town of Queenstown, where the highway meets MD 18 (Main Street) and MD 456 (Del Rhodes Avenue) at a pair of superstreet intersections. Access from southbound US 301 to eastbound US 50 and from westbound US 50 to northbound US 301 is via MD 18 at the Queenstown Premium Outlets. US 301 gradually curves northeast as it passes to the south and east of Centreville, the county seat of Queen Anne's County. The highway has a five-ramp partial cloverleaf interchange with MD 213 (Centreville Road) south of town and a double-roundabout partial cloverleaf interchange with MD 304 (Ruthsburg Road) north of Mill Stream Branch. US 301 has an oblique at-grade crossing of the Centerville Branch of the Northern Line of the Maryland and Delaware Railroad. The highway parallels the railroad through an intersection with MD 305 (Hope Road) at Carville and unsigned MD 834 (Hayden Clark Road), where the median temporarily widens for the Bay Country Welcome Center.[1][7]

US 301 northbound past the MD 299 intersection in Cecil County

US 301 diverges from the railroad at its intersection with MD 405 (Price Station Road) at Price. The U.S. highway continues north through junctions with MD 19 (Roberts Station Road) and the western end of MD 302 (Barclay Road) and a superstreet intersection with MD 300 (Sudlersville Road). US 301 has a four-ramp partial cloverleaf interchange with MD 290 (Dudley Corner Road) just south of Red Lion Branch. The U.S. Highway has a superstreet intersection with MD 544 (McGinnes Road) just west of that highway's eastern end at MD 313 and just south of Unicorn Branch. US 301 crosses the Chester River into Kent County west of Millington. The highway continues through an indirect interchange with MD 291 (River Road); access to MD 291 is via side ramps with two unsigned portions of MD 701, which parallels the northbound and southbound sides of US 301 as Howard Johnson Road and Edge Road, respectively.[1][7]

US 301 has an at-grade railroad crossing with the Chestertown Branch of the Northern Line of the Maryland and Delaware Railroad west of the junction of the two Northern Line branches at Massey. North of the railroad, the U.S. highway has a superstreet intersection with MD 313 (Galena Road) south of Galena. US 301 has a diamond interchange with MD 290 (Galena Sassafras Road) before crossing the Sassafras River into Cecil County west of Sassafras. The highway meets the northern end of MD 299 (Massey Sassafras Road), where there is a weigh station in the southbound direction, and passes to the south of Warwick. US 301 reaches the Maryland–Delaware state line, where it continues northeast into New Castle County along an all-electronic toll freeway.[1][7]