U.S. Route 20

U.S. Route 20
U.S. Route 20
	US 20 highlighted in red; the gap represents the unofficial segment through Yellowstone National Park
Route information
Length	3,365 mi(5,415 km)
Existed	November 11, 1926–present
Major junctions
West end	US 101inNewport, OR
	I-5atAlbany, OR; I-15atIdaho Falls, ID; I-25atCasper, WY; I-35nearWilliams, IA; I-55atHodgkins, IL; I-65/I-90inGary, IN; I-75inPerrysburg, OH; I-79inErie, PA; I-87/I-90nearAlbany, NY; I-95inWaltham, MA;
East end	Route 2inBoston, MA
Location
Country	United States
States	Oregon,Idaho,Montana,Wyoming,Nebraska,Iowa,Illinois,Indiana,Ohio,Pennsylvania,New York,Massachusetts
Highway system
	United States Numbered Highway System; List; Special; Divided;

U.S. Route 20orU.S. Highway 20(US 20) is an east–westUnited States Numbered Highwaythat stretches from thePacific Northwesteast toNew England.The "0" in its route number indicates that US 20 is a major coast-to-coast route. Spanning 3,365 miles (5,415 km), it is the longest road in the United States,^[1]and, in the east, the route is roughly parallel toInterstate 90(I-90), which is the longestInterstate Highwayin the U.S. There is a discontinuity in the official designation of US 20 throughYellowstone National Park,with unnumbered roads used to traverse the park.

US 20 andUS 30break the general U.S. Route numbering rules inOregon,since US 30 actually starts north of US 20 inAstoria,and runs parallel to the north throughout the state (theColumbia RiverandInterstate 84). The tworun concurrentlyand continue in the correct positioning nearCaldwell, Idaho.This is because US 20 was not a planned coast-to-coast route while US 30 was. US 20 originally ended at the eastern entrance of Yellowstone Park; it was extended in 1940.^[1]

The highway's eastern terminus is inBoston, Massachusetts,atKenmore Square,where it meetsMassachusetts Route 2.Its western terminus is inNewport, Oregon,at an intersection withUS 101,within a mile of thePacific Ocean.^[3]

Route description

Oregon

Sign at western origin in Newport, Oregon

US 20 begins at an intersection withUS 101inNewport, Oregon,and runs generally eastward towardsIdaho.On the way it goes over theCentral Oregon Coast Range,through severalWillamette Valleycities includingCorvallisandAlbany,climbs theCascade MountainsoverSantiam Pass,goes throughBend,and traverses theOregon High Desertafter passing throughBurns.It eventually overlapsUS 26inVale,and the two highways continue concurrently to theIdahoborder.

Idaho

US 20 crosses into Idaho from Oregon northwest ofParma.Itruns concurrentlywithUS 26and joinsUS 95through Parma. US 20/US 26 leaves US 95 southeast of Parma and runs toCaldwellwhere US 20/US 26 joins withI-84andUS 30for a short time. These four highways parallel each other (on two roadways) toBoisewhere US 20/US 26 runs through downtown before joining with I-84 and US 30 again toMountain Home,where it departs at exit 95 to head east, pastRattlesnake Station,Anderson Ranch Damroad, and cresting at Cat Creek summit at 5,527 feet (1,685 m)above mean sea level.It continues into and acrossCamas CountythroughFairfieldto Timmerman Junction, the intersection inBlaine CountywithState Highway 75,the route toSun Valley,Galena Summit,andStanley.US 20 continues east throughPicaboandCarey,joined with US 26 andUS 93,toCraters of the MoonandArco,where US 93 splits off and turns north-northwest to climb theBig Lost Rivervalley. US 20/US 26 continues on through theIdaho National Laboratory,where the highways split just west ofAtomic City;US 26 heads toBlackfootand US 20 toIdaho Falls,where it turns north-northeast to pass nearRexburgas a freeway. US 20 then climbs through the communities ofSt. Anthony,Ashton,andIsland Park,and crosses theContinental DivideatTarghee Passat 7,072 feet (2,156 m), enteringMontanawest ofWest Yellowstone.

Montana

In the state of Montana, US 20 runs for less than 10 miles (16 km). It runs from the Idaho state line toWest Yellowstone, Montana,the western entrance toYellowstone National Park.US 20 is known as theTarghee PassHighway in Montana.

While US 20 and other U.S. Routes are officially discontinuous through the park, some commercially produced maps show these highways running inside Yellowstone National Park itself along its unnumbered roads and across the Montana–Wyoming state line.

Wyoming

In the state of Wyoming, the eastern segment of US 20 starts at the eastern entrance toYellowstone National Parkalong with the western termini ofUS 14andUS 16.These three routes run east toGreybull,where US 14 continues east and US 16/US 20 turns south; atWorland,US 16 turns east while US 20 continues south, passing throughWind River Canyonsouth ofThermopolis.US 20 joins US 26 inShoshoni,where it turns east, and they continue all the way throughCasper.From Casper, the two highways parallelI-25andUS 87for 26 miles, until all four link up together just southeast ofGlenrock.These four routes stay combined toOrin,where US 20 turns east from I-25, at the western end ofUS 18.US 18 and US 20 are concurrent from Orin toLusk,where US 18 turns north and US 20 continues east into Nebraska.

Nebraska

US 20 enters Nebraska from Wyoming

WithinNebraska,US 20 is astate highwaythat begins on theWyoming–Nebraska state line west ofHarrisonnear theNiobrara Riverand runs to the Nebraska–Iowastate line inSouth Sioux City.Throughout its 431.60-mile (694.59 km) length the route passes through a diverse range of landscapes includingbluffsandescarpmentsin the NorthwestPanhandle,theNebraska Sandhillsin the northern part of the state, and rolling hills and plains through Randolph, Nebraska as the highway approaches theMissouri Rivervalley south ofSioux City, Iowa.^[4]^[5]Throughout its length, US 20 is a two-lane highway with the exception of the easternmost 8.45 miles (13.60 km) which is four-lane divided highway, the last 3.21 miles (5.17 km) of which is concurrent withInterstate 129.^[6]

Iowa

US 20 crosses the Mississippi River connecting Dubuque, Iowa, and East Dubuque, Illinois

US 20 enters Iowa atSioux Cityvia theMissouri Rivercrossing withI-129andUS 75.After skirting the southeast side of Sioux City as a freeway with US 75, US 20 continues east as anexpresswaytoMoville.From Moville through north of Early at the junction with U.S. Route 71 andIowa Highway 471,US 20 was reconstructed from a rural two-lane highway to a four-lane road. This segment re-opened October 19, 2018 and made it so that US 20 is a continuous four-lane highway for its entire length in Iowa. It passes to the north ofSac City,where it has another interchange with the realignedU.S. Route 71,then passes to the south ofFort DodgeandWebster Citybefore intersectingI-35nearWilliams.

A new segment of freeway betweenUS 65south ofIowa FallsandIowa Highway 14opened in 2003 creating a continuous four-lane route from Moorland to Dubuque. The new segment shaved 16 miles (26 km) off US 20's length in Iowa. In theWaterloo/Cedar Fallsarea, the segment of US 20 overlapped by theAvenue of the Saints,which is also designated as Iowa Highway 27. US 20 passesIndependence,Manchester,andDyersvillebefore reachingDubuque.At Dubuque, US 20 crosses into Illinois over theJulien Dubuque Bridge.

Illinois

In the state of Illinois, US 20 begins inEast Dubuque,following southeastward along the Mississippi River, and continues into the very hillyDriftless Areaof northwest Illinois throughGalenaandElizabeth.The highway then transitions eastward from the Driftless Area to the Interior Plains nearStockton.The road continues as a bypass north ofFreeport,and then runs as a freeway along the southern fringe ofRockford.From Rockford toChicago, Illinois,US 20 is a mixture of four-lane expressway, four-lane limited access freeway, and winding two-lane surface road. It is signed as "General U.S. Grant Highway" afterUlysses S. Grant.U.S. 20 runs through the south side of Chicago as 95th Street. US 20 exits Illinois along withUS 12andUS 41as Indianapolis Boulevard south of theChicago Skyway.

Indiana

Looking eastbound at US 20 as it meets State Road 127 in a traffic circle in Angola, Indiana

In the state of Indiana, US 20 enters from the west beneath theChicago Skywaywith US 12 and US 41. US 20 passes through heavily industrialized northwestern Indiana and is the main east–west artery throughGary.It then parallels US 12 to just west ofMichigan Citybefore running due east throughNew CarlisletoSouth Bend.US 20 travels around South Bend andElkharton theSt. Joseph Valley Parkway,a four-lane limited access freeway, then returns to surface road east of Elkhart. US 20 then passes throughLaGrangeandAngola,intersecting withI-69before leaving Indiana just north of the eastern terminus of theIndiana Toll Road.

FromGarytoSouth Bend,US 20 was built as the Dunes Relief Road. During the 1930s and 1940s the Dunes Highway,US 12,was becoming more crowded as housing lots and communities developed in the Indiana Dunes. Today, there are numerous communities along US 20 and the lakefront, including Gary,Portage,Burns Harbor,Porter,Chesterton,Pines,andMichigan City.

Most notably, the route is one of the main access roads toIndiana Dunes National Park.

Ohio

Sign for US 20 along with the sign for State Route 7 in Conneaut, Ohio

US 20 entersOhiofrom Indiana just west ofColumbiaand traverses east throughPioneerandAlvordtontoFayette.It continues east throughOakshade,Assumptionand becomes five-lane, non-limited access roadway intoSylvaniatoToledo,and then turns south until into the Toledo suburb ofMaumee.After Maumee, US 20 crosses Maumee River curving back east becoming 2 lanes throughPerrysburgtoWoodville,where it becomes a four-lane, non-limited access highway. It bypassesFremontwhile concurrent withUS 6,State Route 53,andState Route 19,and then travels through the northern edge ofClydeand the downtown area ofBellevue,where it is joined byState Route 18.From there the four-lane highway continues throughMonroevilleand bypassesNorwalk,then becomes a two-lane highway from there toOberlin.Continuing east, US 20 traverses throughElyria,North Ridgeville,Westlake,Rocky River,LakewoodandCleveland,where it goes right throughPublic Square.East of Cleveland US 20 follows the southern shore ofLake Erie,followingEuclid Avenuefrom Public Square, and traversesEuclid,Wickliffe,where it intersects with I-90,Mentor,Painesville,Madison,Geneva,Ashtabulaand crosses intoPennsylvaniaatConneaut.

Pennsylvania

I-79 at US 20 (exit 182) in Erie, Pennsylvania

US 20 runs for nearly 50 miles (80 km) acrossErie County, Pennsylvania,most of that time just south of theCSX/Amtrakrailroad tracks. US 20 appears as West Ridge Road eastward from the Ohio border throughSpringfield,Girard,FairviewandMillcreektownships. At the intersection withPennsylvania Route 832,just outside theEriecity limits, it becomes West 26th Street. After it reaches city center at the intersection with State Street, it becomes East 26th Street. It turns sharply northward as Broad Street at theBayfront Connector,then turns east again as Buffalo Road throughWesleyvilleandHarborcreek Township.Buffalo Road turns sharply northward at the town of Harborcreek. US 20 intersects with Pennsylvania Route 955 and resumes its eastward journey. AtNorth East Township,US 20 becomes West Main Road. Within the town limits, it becomes West Main Street until it reaches the town center at its intersection with Pennsylvania Route 89, where it becomes East Main Street. Outside the town limits it becomes East Main Road until it reaches Pennsylvania's border withNew York.

New York

US 20 marker, east of Sangerfield, New York

InNew York,US 20 runs roughly parallel to theNew York State Thruway(I-90) throughout the state. The route runs concurrently withNew York State Route 5twice, with the second overlap extending 68 miles (109 km) acrossWesternandCentral New YorkfromAvontoAuburnrunning along the top of theFinger LakescrossingCanandaiguaandSeneca Fallsalong the way. US 20 runs across the ruralCherry Valley TurnpikebetweenSkaneatelesandAlbany.US 20 was also known as the Boston-Buffalo highway prior to the construction of the New York Thruway and Massachusetts Turnpike.

Massachusetts

Sign forRoute 20atKenmore Square,near theBoston Citgo sign

In Massachusetts, US 20 runs roughly parallel to I-90Mass Pike,intersecting it directly at exit 10 and indirectly at exit 94.

In part ofBerkshire County,US 20 runs north–south as it runs concurrently withUS 7.It is known as the "Jacob's Ladder Trail" as it crosses theBerkshire HillsbetweenLeein Berkshire County andChesterinHampden County.From Chester toWestfield,US 20 and theBoston and Albany Railroadfollow theWestfield Riverdown to the broad valley of theConnecticut River.

InSpringfield,US 20 runs concurrently withI-291between Plainfield Street and Page Boulevard; it follows Boston Road as it leaves Springfield and travels through the town ofWilbraham,eventually becoming Main Street inPalmer.

InShrewsbury,US 20 is called "Hartford Turnpike". InNorthborough,andWorcesterit is called "Southwest Cutoff", until it merges with the originalBoston Post Roadin Northborough (Southwest Cutoff and West Main Street). Southwest Cutoff was created at the turn of the century to bypass truck traffic around Shrewsbury center as well as connecting to theBoston and Worcester Turnpike.

In parts of eastern Massachusetts, US 20 follows the route of the oldBoston Post Roadand passes byLongfellow's Wayside Inn,inSudbury,the oldest continually operated Inn in America. In 1926, after engineers determined that heavy truck traffic on the Boston Post Road was damaging the foundations of the Inn,Henry Ford,then owner and proprietor, ordered the construction of the mile-and-a-half-long Route 20 bypass. Upon its completion on December 11, 1928, he sold it to the Commonwealth of Massachusetts for $1 and never cashed the check. According to theBoston Heraldthe by-pass cost Ford $288,000, equivalent to roughly $4.7 million in 2021.^[7]The original route of US 20 is now called Wayside Inn Road.

US 20 continues from Sudbury throughWayland,Weston,Waltham,Watertownand then intoBostonthroughAllstonandFenway–Kenmore.U.S. Route 20's official eastern terminus is inKenmore Squareat the intersection ofCommonwealth Avenue,Beacon Street,andBrookline Avenue,where the alignment becomesMassachusetts Route 2.Route 2 continues for a short distance where it terminates atMassachusetts Route 28.

History

Before the U.S. Highway System, the route in New England and New York was designated as New England Interstate Route 5 (NE-5), part of theNew England Interstate Routesystem that existed between 1922 and 1927. Around 1923, from Springfield to Pittsfield, NE-5 was known as "Jacob's Ladder",^[8]and from Boston to Albany, the "Hubway". When US 20 was first commissioned, it took over the entirety of NE-5.

Historic termini

Until 1940, the western endpoint of US 20 was the east entrance toYellowstone National Park.

Historic routes

BetweenFort Dodge, Iowa,andDubuque, Iowa,the route has been widened to four lanes, the last link of this completed in 2003. Much of the old route is a few miles north of the present route except betweenI-35andWaterloo.There, the old route is farther north, going throughIowa Falls,Aplington,and the north side ofCedar Fallsalong what is nowIowa Highway 57.

From just west ofSouth Bend, Indiana,to the St. Joseph – Elkhart county line, the old route of US 20 throughSt. Joseph Countyis now Business US 20. InElkhart County,its old route is now classified as a county road and is simply called Old US 20. TheSt. Joseph Valley Parkwayis the present route of US 20 in the South Bend – Elkhart Area.

From 1930 to 1933, US 20 followed what are nowMassachusetts Route 67andMassachusetts Route 9fromWorcestertoPalmerviaShrewsburyandNorthborough.^[9]

The 1953 Massachusetts Department of Public Works Master Plan would have relocated US 20 betweenPalmer, Massachusettsand eitherWest Springfield, MassachusettsorWestfield, Massachusettsalong the right-of-way now used by theMassachusetts Turnpike,but this was never implemented.^[10]

Until 1970–72,^[9]US 20 followed an old route through downtown Springfield—Boston Road and State Street—crossing the Connecticut River via the olderMemorial Bridge(nowMassachusetts Route 147). The construction ofI-291prompted a change. US 20 now crosses from West Springfield at the North End Bridge, and is co-signed with I-291 until Page Boulevard, where it heads back to Boston Road via the former route of 20A.

In 2012, the Historic US Route 20 Association was formed to identify, promote and preserve the history of the route and original alignments that were once signed "Route 20" fromBostontoNewport.^[11]

Historic names

The portion of US 20 eastward from Illinois generally follows the path of theYellowstone Trail.
InMassachusetts,US 20 follows theBoston Post RoadinWaylandandSudbury.
In the state ofNew York,part of US 20 follows the oldCherry Valley Turnpikeand is still referred to by that name in some places.
From Buffalo westward toCleveland, Ohio,US 20 follows the path of the Buffalo Stage Road.^[12]

One of the 1842milestonesmarking the original Western Reserve and Maumee Turnpike in Woodville, Ohio.

BetweenFremont,Ohio andPerrysburg,Ohio, the road dates back to the late 1830s. It was known then as the Maumee andWestern ReserveRoad. Nicknamed "Mud Pike" as it cut through theGreat Black Swamp,it earned a reputation as "the worst road on the continent" for the mudholes that would trap wagon wheels and slow draft animals. Travelers sometimes would take three days to travel 1 mile (1.6 km). It is still signed as Maumee St. in and near Angola, IN.
Through westernIndiana,US 20 was built as the Dunes Relief Road, as it bypassed the heavily traveledDunes Highway.
Northwest ofChicagoit is called Ulysses S. Grant Highway.
On March 25, 2019, Idaho officially labeled their section of US 20 as the Idaho Medal of Honor Highway in honor of 48 Medal of Honor Recipients with strong Idaho attachments.

Major intersections

Western segment

Oregon: US 101at West Olive Street inNewport; I-5inAlbany; US 97inBend; US 395inRiley.The highways travel concurrently to northeast ofBurns.; US 26inVale.The highways travel concurrently toMountain Home, Idaho.
Idaho: US 95north ofParma.The highways travel concurrently to southeast of Parma.; I-84/US 30north ofCaldwell.The highways travel concurrently to Caldwell.; I-184inBoise.The highways travel concurrently through the city.; I-84/US 30in Boise. The highways travel concurrently toMountain Home.; US 26/US 93inCarey.US 20/US 26 travel concurrently to northwest ofAtomic City.US 20/US 93 travel concurrently toArco.; I-15inIdaho Falls.The highways run concurrently for about 1 mile between exits 118 and 119
Montana: US 191/US 287at Firehole Avenue inWest Yellowstone.The highways travel concurrently to the West Entrance toYellowstone National Park.

Yellowstone National Park segment (unofficial designation)

US 191/US 287travels concurrently from the park's West Entrance toWest Thumb.

US 89north-northwest of West Thumb. The highways travel concurrently to West Thumb.

US 14/US 16in West Thumb. The highways travel concurrently to the park's East Entrance.

Eastern segment

Wyoming: US 14/US 16at the East Entrance to Yellowstone National Park, southeast ofPahaska Tepee.US 14/US 20 travel concurrently toGreybull.US 16/US 20 travel concurrently toWorland.; US 310west-northwest ofGreybull; US 26inShoshoni.The highways travel concurrently toOrin.; I-25/US 87at Events Drive on theCasper–Hartrandtcity line. I-25/US 20 travel concurrently into Casper proper. US 20/US 87 travel concurrently toOrin.; I-25in Casper; I-25southeast ofGlenrock.The highways travel concurrently toOrin.; I-25/US 18/US 26/US 87inOrin.US 18/US 20 travel concurrently toLusk.; US 85inLusk.The highways travel concurrently through the town.
Nebraska: US 385west ofChadron.The highways travel concurrently to Chadron.; US 83inValentine.The highways travel concurrently to south-southeast of Valentine.; US 183west-northwest ofLong Pine.The highways travel concurrently toBassett.; US 281inO'Neill.The highways travel concurrently through the city.; US 275/US 281in O'Neill. US 20/US 275 travel concurrently to southeast ofInman.; US 81west-southwest ofRandolph; I-129/US 75/US 77inSouth Sioux City.I-129/US 20 travel concurrently toSioux City, Iowa.US 20/US 75 travel concurrently to theWoodbury–Concordtownship line.
Iowa: I-29/I-129inSioux City; US 59inHolstein.The highways travel concurrently to southeast of Holstein.; US 71inBoyer Valley Township.; US 169inElkhorn Township; US 69inLiberty Township; I-35inRose Grove Township; US 65inEllis Township; US 63inWaterloo; I-380/US 218in Waterloo. I-380/US 20 travel concurrently toPoyner Township.; US 52inDyersville.The highway travels concurrently toDubuque.; US 61/US 151inDubuque
Illinois: I-39/US 51inRockford.The highways travel concurrently toCherry Valley.; I-90north-northeast ofHampshire; I-355inAddison; I-290inElmhurst.The highways travel concurrently through the city.; US 12/US 45on theStone Park-Melrose Parkcity line. US 12/US 20 travel concurrently toEast Chicago, Indiana.US 20/US 45 travel concurrently to west of thePalos Hills-Hickory Hillscity line.; I-290on theBellwood-Hillside-Westchestercity line; US 34inLa Grange; I-55on theCountryside-Hodgkinscity line; I-294inWillow Springs; I-294on theHickory Hills-Bridgeviewcity line; US 41inChicago.The highways travel concurrently toWhiting.
Indiana: I-90northwest ofWhiting; US 12on theHammond-Garycity line. The highways travel concurrently into Gary proper.; I-65in Gary; I-90in Gary; I-94inBurns Harbor; US 421inMichigan City; I-94east-southeast of Michigan City; US 35east-southeast of Michigan City; US 31inSouth Bend.The highways travel concurrently through the city.; US 33inElkhart; I-69inAngola
Ohio: US 127inMill Creek Township.The highways travel concurrently toGorham Township.; I-475/US 23inSylvania; I-80/I-90inMaumee; US 24in Maumee; I-75/US 23inPerrysburg.US 20/US 23 travel concurrently to theTroy-Woodvilletownship line.; US 6inSandusky Township.The highways travel concurrently toFremont.; US 250inNorwalk; US 6inLakewood.The highways travel concurrently toCleveland.; US 6/US 42/US 322/US 422in Cleveland. US 20/US 422 travel concurrently for one block.; US 6inEast Cleveland.The highways travel concurrently toEuclid.; I-90on theEuclid-Wickliffecity line
Pennsylvania: US 6NinSpringfield Township; I-79inErie; US 19in Erie; I-90east-northeast ofNorth East
New York: I-90inHanover; I-390east ofAvon; I-81south-southwest ofLaFayette; US 11south of LaFayette; I-87inMcKownville; US 9WinAlbany; US 9in Albany. The highways travel concurrently toSchodack.; US 4inEast Greenbush; I-90inSchodack
Massachusetts: US 7inPittsfield.The highways travel concurrently toLenox.; I-90inLee; US 202inWestfield.The highways travel concurrently through the city.; US 5inWest Springfield; I-91inSpringfield; I-291in Springfield. The highways travel concurrently through the city.; I-84inSturbridge; I-395/I-290inAuburn; I-495inMarlborough; I-95inWaltham; Route 2inBoston