Sixth Street / Whittier Blvd over the Los Angeles River (Los Angeles County, California)
Built 1932
Steel arch bridge over Los Angeles River on Sixth Street in Los Angeles
Open to traffic

Sixth Street Bridge (Minnehaha County, South Dakota)
Built 1975
Bridge over Big Sioux Rv on Sixth Street E of Phillips Ave. in Sioux Falls
Open to traffic

Skiberene Bridge (Clatsop County, Oregon)
Built 1930
Stringer bridge over Necanicum River on U.S. 101/U.S. 26
Open to traffic

Skillet Fork Bridge (Marion County, Illinois)
Built 1915
Through truss bridge over Skillet Fork on CH 30
Open to traffic

Skillet Fork Bridge (Marion County, Illinois)
Built 1946
Through truss bridge over Skillet Fork Creek on FAS 795, 1 mi. west of Helm
Open to traffic

Slagle Creek Bridge (Bollinger County, Missouri)
Built ca. 1925 by Miller & Borcherding Bridge Builders of St. Louis, the company that built Hargrove Bridge using the same patented truss design
Pony truss bridge over Slagle Creek on CR 714 near the intersection with CR 720 southwest of Arab
Open to traffic on a gravel road with a 4 ton weight limit

Smalling Bridge (Carter County, Tennessee)
Built 1941
Pratt Truss bridge over Watauga River on Smalling Road
Open to traffic, one-lane bridge

Smart Ditch Bridge (Jackson County, Indiana)
Through truss bridge over Smart Ditch on CR 600 East
Open to traffic

Smith Branch MO 161 Bridge (Montgomery County, Missouri)
Built 1934
Pony truss bridge over Smith Branch on MO 161
Open to traffic

Smith Covered Bridge (Rush County, Indiana)
Built 1877 by A. M. Kennedy; rehabilitated 1996
Covered bridge over Flatrock River on CR 150 North
Open to traffic

Smith Creek MO 94 Bridge (Warren County, Missouri)
Built 1934
Pony truss bridge over Smith Creek on MO 94
Open to two-lane traffic

Smith Creek Road Bridge (Moniteau County, Missouri)
Built ca. 1930
Pony truss bridge over Smith Creek on Smith Creek Road southwest of California
Open to traffic

Smith Road Bridge (Rock County, Wisconsin)
Built 1910
Single lane Pratt through truss bridge over Turtle Creek on Smith Road
Open to traffic

Smithfield Bridge (Delaware County, Indiana)
Built 1902
Through truss bridge over White River on CR 170 South
Open to traffic

Smithfield Street Bridge (Allegheny County, Pennsylvania)
Built 1883 under the direction of engineer Gustav Lindenthal
Two-span lenticular through truss bridge over Monongahela River on Smithfield Street in Pittsburgh
Open to four lanes of traffic

Smithland Bridge (Livingston County, Kentucky)
Built 1931; rehabilitated 1954
Through truss bridge over Cumberland River on US 60 at Smithland
Open to traffic

Smoky Hill River Bridge (McPherson County, Kansas)
Built 1919; rehabilitated 1989
Through truss bridge over Smoky Hill River on Syensk Road
Open to traffic

Smoky Hill River K-147 Bridge (Trego County, Kansas)
Built 1952; rehabilitated 1993
Steel through arch over Smoky Hill River on K-147 at Cedar Bluff Lake Spillway
Open to traffic

Smyrna Road Bridge (Christian County, Missouri)
Built 1912 by the Canton Bridge Co. of Canton, Ohio
Through truss bridge over Finley Creek on Smyrna Road northeast of Ozark
Open to one-lane traffic on a paved road

Snag Creek Bridge (Cedar County, Missouri)
Built ca. 1910
Pony truss bridge over Snag Creek on CR 1101
Open to traffic

Sni-A-Bar Creek Bridge (Lafayette County, Missouri)
Built 1929
Through truss bridge over Sni-A-Bar Creek on MO 224 (Old US 24) at Wellington
Open to traffic

Sni-A-Bar Creek Route D Bridge (Lafayette County, Missouri)
Built 1934
Pony truss bridge over Sni-A-Bar Creek on Route D
Open to traffic

Snow Hill Covered Bridge (Franklin County, Indiana)
Built 1894 by William Butts and John Horn; rehabilitated 1987
Covered bridge over Johnson Fork Whitewater River on Snow Hill Road
Open to traffic

Snowden Bridge (Richland County, Montana)
Built 1914; retrofitted to also allow vehicular toll traffic in 1925
Vertical-lift through truss bridge over the Missouri River on the BNSF Railroad
Open to railroad traffic

Snyder Covered Bridge (Columbia County, Pennsylvania)
Built 1876
Covered bridge over Roaring Creek on Rarig Road, southeast of Catawissa
Open to traffic

Soledad Canyon Road over the Santa Clara River (Los Angeles County, California)
Built 1952
Steel stringer bridge over Santa Clara River on Soledad Cyn Road
Open to traffic

Soledad Canyon Road over UPRR Tracks (Los Angeles County, California)
Built 1938
Rainbow arch bridge over UP Railroad on Soledad Canyon Road
Open to traffic

Sonestown Covered Bridge (Sullivan County, Pennsylvania)
Built 1900; rehabilitated 2001
Covered bridge over Muncy Creek on Champion Road (TR 310)
Open to traffic

Sonora Road Bridge (Preble County, Ohio)
Built 1902
Through truss bridge over Twin Creek on TR 455
Open to traffic

Sorrel Creek Bridge (Garland County, Arkansas)
Built 1930 by the West Arkansas Construction Co. of McAlister, Oklahoma
Small concrete arch bridge over Sorrel Creek on AR 7
Open to two-lane traffic

Soto Street Bridge over the Los Angeles River (Los Angeles County, California)
Built 1928; rehabilitated 1987
Concrete arch bridge over Los Angeles River on Soto Street in Vernon
Open to traffic

Soto Street over Huntington Drive South (Los Angeles County, California)
Built 1936
Girder bridge over Mission Rd-Huntington So on Soto Street in Los Angeles
Open to traffic

Soto Street over Valley Blvd. (Los Angeles County, California)
Built 1936
Steel stringer bridge over Valley Blvd/Sptco on Soto Street in Los Angeles
Open to traffic

South Big River Bridge (St. Francois County, Missouri)
Built 1924; made obsolete by new bridge in 1957
Through truss bridge over Big River on Old US 67 in Desloge
Open to two-lane traffic

South Boat Ditch Bridge (Clark County, Arkansas)
Built ca. 1928
Through truss bridge over South Boat Ditch on CR 8
Open to one-lane traffic

South Boat Ditch US 67 Bridge (Clark County, Arkansas)
Built 1931 by the Virginia Bridge & Iron Co. of Roanoke, Virginia
Pony truss bridge over South Boat Ditch on US 67
Open to two-lane traffic

South Boston Road Bridge (Washington County, Indiana)
Built ca. 1930
Pony truss bridge over Middle Fork Blue River on Canton/S. Boston
Open to traffic

South Branch Little Wolf River Bridge (Waupaca County, Wisconsin)
Built 1907
Stone arch bridge over South Branch Little Wolf River on Mill Street in Scandinavia
Open to traffic

South Cicero Avenue Bridge (Cook County, Illinois)
Built 1927; widened and rehabilitated 1966
Bascule bridge over the Chicago S&S Canal on S. Cicero Avenue (IL 50) in Chicago
Open to four lanes of traffic

South Deer Creek Bridge (Douglas County, Oregon)
Built 1967
Truss bridge over South Deer Creek on CR 16
Open to traffic

South Fork 186A Bridge (Christian County, Illinois)
Pony truss bridge over South Fork Sangamon River on TR 186A, 5 mi. southwest of Rosamond
Open to traffic

South Fork Blue River IN 60 Bridge (Washington County, Indiana)
Built 1937
Concrete arch bridge over South Fork Blue River on IN 60 in New Pekin
Open to traffic

South Fork Blue River Main Street Bridge (Washington County, Indiana)
Built 1884; rehabilitated 1987 and 2007
Through truss bridge over South Fork Blue River on Main Street in New Pekin
Open to traffic

South Fork Bridge (Christian County, Illinois)
Pony truss bridge over South Fork Sangamon River on TR 343, 8 mi. west of Rosamond
Open to traffic

South Fork Bridge (Christian County, Illinois)
Pony truss bridge over South Fork Sangamon River on TR 307A, 7 mi. east of Morrisonville
Open to traffic

South Fork Cane Creek Bridge (Carter County, Missouri)
Built 1922
Pony truss bridge over South Fork of Cane Creek south of Ellsinore on CR 256 (Old US 60)
Open to traffic with no posted weight limit

South Fork Creek Bridge (Fayette County, Illinois)
Built ca. 1930; rehabilitated 1950
Pony truss bridge over South Fork Creek on TR 189, 6 mi. north of Brownstown
Open to traffic

South Fork Holston River CSX Railroad Bridge (Sullivan County, Tennessee)
Built in 1907 as part of first segment of the South & Western RR, later the Carolina, Clinchfield & Ohio, later the Clinchfield, now the CSX Railroad
Howe Truss railroad bridge over the South Fork Holston River on the CSX (formerly Clinchfield) Railroad
Open to rail traffic

South Fork Pottawatomie Creek Bridge (Anderson County, Kansas)
Built 1934
Concrete pony arch bridge over South Fork Pottawatomie Creek, 0.5 mi. south and 3.7 mi. east of Garnett
Open to traffic

South Fork Powder River Bridge (Johnson County, Wyoming)
Built 1932
Deck truss bridge over South Fork Powder River on I-25 West Service Road (Old US 87) at Milepost 246.30
Open to traffic

South Fork Root River Bridge (Fillmore County, Minnesota)
Built 1931
Pony truss bridge over South Fork Root River on MN 43
Open to traffic

South Fork TR 343 Bridge No. 2 (Christian County, Illinois)
Pony truss bridge over South Fork Sangamon River on TR 343, 8 mi. west of Rosamond
Open to traffic

South Fork US 421 Bridge (Clinton County, Indiana)
Built 1940; rehabilitated 1985
Pony truss bridge over South Fork Wildcat Creek on US 421
Open to traffic

South Fork US 65 Bridge (Van Buren County, Arkansas)
Built 1931 by M.K. Orr of Little Rock; rehabilitated 1962
Three-span cantilevered deck truss bridge over South Fork Little Red River on US 65 in Clinton
Open to traffic

South Gabouri Creek Bridge (Ste. Genevieve County, Missouri)
Built 1934, replacing an earlier through truss bridge
Concrete bridge over South Fork Gabouri Creek on Fourth Street in Ste. Genevieve, just beyond the end of MO 32
Open to two-lane traffic

South Harpeth River TN 100 Bridge (Davidson County, Tennessee)
Built 1929
Through truss bridge over South Harpeth River on TN 100 in Nashville
Open to traffic

South Holston River Bridge (Sullivan County, Tennessee)
Built 1950
Through truss bridge over South Holston River on U.S. 421 (State Highway 34)
Open to traffic

South Island Bridge (Will County, Illinois)
Pony truss bridge over East Branch Kankakee River on West Street, 0.25 mi. north of Kahler Rd
Open to one-lane traffic

South Lafave River AR 7 Bridge (Perry County, Arkansas)
Built 1933 by McEachin and McEachin, Inc., of Little Rock
Two-span pony truss bridge over South Fourche Lafave River on AR 7
Open to two-lane traffic

South Moreau Creek Route D Bridge (Cole County, Missouri)
Built 1956
Through truss bridge over South Moreau Creek on Route D
Open to one-lane traffic

South River CR 402 Bridge (Marion County, Missouri)
Built ca. 1930, replacing an earlier bridge
Pony truss bridge over South River on CR 402, east of Palmyra
Open to one-lane traffic

South Umpqua River I-5 Bridge (Douglas County, Oregon)
Built 1965; rehabilitated 1983
Deck truss bridge over South Umpqua River on Southbound I-5
Open to traffic

South Wea Creek Bridge (Miami County, Kansas)
Built 1915
Concrete arch bridge over South Wea Creek, 3.0 mi. south and 0.6 mi. west of Louisburg
Open to traffic

Sparkman Street Bridge (Morgan County, Alabama)
Built 1915
Concrete arch bridge over Shoal Creek on Sparkman Street in Hartselle
Open to traffic

Speakman Covered Bridge (Chester County, Pennsylvania)
Built 1881
Covered bridge over Buck Run T Branch on Frog Hollow Road
Open to traffic

Spencer Creek Covered Bridge (St. Charles County, Missouri)
Built 1976 by Roger Adams
Replica covered bridge over Spencer Creek at Spencer Creek Subdivision in St. Peters
Open to traffic

Spencerville Covered Bridge (De Kalb County, Indiana)
Built 1873 by John McKay
Covered bridge over Saint Joseph River on CR 68
Open to traffic

Spider Leg Bridge (Crawford County, Kansas)
Built in 1914 to replace a wooden bridge.
Closed-spandrel arch bridge over Branch of West Fork Dry Wood Creek on Saint Louis-San Francisco Railroad
Open to traffic

Spillman Creek Bridge (Lincoln County, Kansas)
Built ca. 1910
Pony truss bridge over Spillman Creek, 1.3 mi. north and 2.0 mi. east of Vesper
Open to traffic

Spillman Creek Bridge (Lincoln County, Kansas)
Built ca. 1930
Stone arch bridge over Spillman Creek, 3.5 mi. south and 0.3 mi. east of Ash Grove
Open to traffic

Spillman Creek Bridge (Lincoln County, Kansas)
Built 1912
Through truss bridge over Spillman Creek, 3.7 mi. west of Lincoln
Open to traffic

Splice Creek Road Bridge (Moniteau County, Missouri)
Built or relocated here ca. 1930
Pony truss bridge over Splice Creek on East Splice Creek Road near Lupus
Open to one-lane traffic

Split Rock Bridge (Pipestone County, Minnesota)
Built 1938 by the Works Progress Administration
Stone arch bridge at Split Rock Creek State Park on CR 54
Open to traffic

Spoil Bank Railroad Bridge (Stoddard County, Missouri)
Built 1935; west approach reconstructed 1975
Two-span pony plate girder bridge over the Spoil Bank drainage ditch on the Union Pacific Railroad, west of Morehouse
Open to traffic

Sprague River Bridge I (Klamath County, Oregon)
Built 1944
Bridge over Sprague River on Sprague River Highway in Sprague River
Open to traffic

Sprague River Bridge II (Klamath County, Oregon)
Built 1944
Concrete deck girder bridge over Sprague River on Sprague River Highway
Open to traffic

Spring Branch Bridge (Benton County, Arkansas)
Built 1932
Small concrete bridge over Spring Branch on AR 72 in Lundell
Open to traffic

Spring Creek 1900N Bridge (Iroquois County, Illinois)
Built 1916
Through truss bridge over Spring Creek on 1900N Road
Open to traffic

Spring Creek Branch 1250N Bridge (Iroquois County, Illinois)
Built 1904
Two-span bedstead pony truss bridge over a branch of Spring Creek on 1250N Road
Open to one-lane traffic

Spring Creek Bridge (Atchison County, Kansas)
Built ca. 1930
Pony truss bridge over Spring Creek, 1.0 mi. west and 1.6 mi. north of Arrington
Open to traffic

Spring Creek Bridge (Lincoln County, Kansas)
Built ca. 1930
Pony truss bridge over Spring Creek, 4.0 mi. south and 3.4 mi. east of Vesper
Open to traffic

Spring Creek Bridge (Rockingham County, Virginia)
Built 1925 by the Champion Bridge Co.
Pony truss bridge over Spring Creek on Route 748 at Spring Creek
Open to one-lane traffic

Spring Creek CR 519 Bridge (Maries County, Missouri)
Built ca. 1930
Concrete tee beam bridge over Spring Creek on CR 519
Open to traffic

Spring Lake Bridge (Yell County, Arkansas)
Built 1936 by the United States Resettlement Administration (WPA)
Small two-span stone arch bridge over Bob Barnes Branch at Spring Lake Recreation Area
Open to traffic

Spring River CR 1040 Bridge (Lawrence County, Missouri)
Built ca. 1930
Through truss bridge over Spring River on CR 1040
Open to traffic

Spring River CR 2130 Bridge (Lawrence County, Missouri)
Pony truss bridge over Spring River on CR 2130
Open to one-lane traffic

Spring River CR 74 Bridge (Fulton County, Arkansas)
Built 1916 by H.B. Walton
Five-span concrete deck girder bridge over Spring River on CR 74 (Old US 63) in Mammoth Spring
Open to one-lane traffic

Spring River Old US 60 Bridge (Lawrence County, Missouri)
Built 1927
Concrete tee beam bridge over Spring River on Business US 60 near Verona
Open to two-lane traffic

Spring River Route D Bridge (Jasper County, Missouri)
Pony truss bridge over Spring River on Route D southwest of Purcell
Open to two-lane traffic

Spring River Route O Bridge (Jasper County, Missouri)
Built 1935
Through truss bridge over Spring River on Route O
Open to two-lane traffic

Spring Road Bridge (Grundy County, Illinois)
Built 1910
Three-span concrete girder bridge over Mazon River on Spring Road (TR 105), .3 mi. east of Campbell Rd
Open to one-lane traffic

Spring Street Bridge (Whitman County, Washington)
Built 1915
Concrete arch bridge over South Fork Palouse River on Spring Street in Pullman
Open to traffic

Spring Street Bridge (Chippewa County, Wisconsin)
Built 1916; Placed on NRHP 1982
Rainbow arch bridge over Duncan Creek on Spring Street in Chippewa Falls
Open to traffic

Spring Street Bridge (Crawford County, Missouri)
Built 1937 by the Works Progress Administration
Stringer bridge over Yadkin Creek on Spring Street in Steelville
Open to one-lane traffic with a 15 ton weight limit

Spring Street Bridge (Floyd County, Indiana)
Built ca. 1920
Four-span concrete arch bridge over Silver Creek on Spring Street in Clarksville
Open to traffic

Spring Street Bridge (Garland County, Arkansas)
Concrete arch bridge over Gulpha Creek on Spring Street in Hot Springs
Open to two-lane traffic

Spring Valley Bridge (Bureau County, Illinois)
Built 1934; rehabilitated 1989
Five-span through truss bridge over the Illinois River on IL 89 south of Spring Valley
Open to two-lane traffic

Spring Valley Road Bridge (Miami County, Kansas)
Built ca. 1920
Pony truss bridge over North Wea Creek, 2.2 mi. north and 2.0 mi. west of Louisburg
Open to traffic

Springfield Bridge (Lane County, Oregon)
Built 1929
Through truss bridge over Willamette River on Westbound OR 126 in Springfield
Open to traffic

SPRR Bridge over Victory Place (Los Angeles County, California)
Built 1932
Bridge over Victory Place on Southern Pacific, Amtrak, and Metrolink in Burbank
Open to Traffic