Total bridges
136
Public highway bridges in Lawrence County
County profile · official public datasets
136 public highway bridges tracked in the FHWA National Bridge Inventory: 36% rated Good, 51.5% Fair, 12.5% Poor.
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Lawrence County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.
According to the Federal Highway Administration's 2024 National Bridge Inventory, Lawrence County ranks #27 of 66 South Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 12.5%). Lawrence County, South Dakota contains 136 public highway bridges. Roughly 36% are rated “Good,” 51.5% “Fair,” and 12.5% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.
Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.
Source: FHWA National Bridge Inventory. See methodology for full definitions.
Total bridges
136
Public highway bridges in Lawrence County
Good condition
36%
49 of 136 rated 7-9
Fair condition
51.5%
70 of 136 rated 5-6
Poor condition
12.5%
17 of 136 rated 4 or below
In-state Poor-share rank
#27 of 66
Among South Dakota counties with 5+ bridges, lower share ranks better
Share of 136 NBI-tracked bridges by lowest applicable component rating.
That is 2% of the county's reported daily bridge traffic on 12.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 470 crossings a day against 2,647 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.
Computed over the 136 of 136 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
67 of the 136 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 36% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.
Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.
COUNTY RD 014B over MILLER CK, built 1934, carries 2,000 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 17-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 7,993 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
136 bridges with a recorded construction year, grouped by decade
1900–1909
2 bridges
1930–1939
5 bridges
1940–1949
3 bridges
1950–1959
3 bridges
1960–1969
18 bridges
1970–1979
49 bridges
1980–1989
8 bridges
1990–1999
20 bridges
2000–2009
17 bridges
2010–2019
5 bridges
2020–2029
6 bridges
What this shows Construction peaked in the 1970s, when 49 of the county's bridges still in the inventory were built, which is 36% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1980, 5 years newer than the South Dakota average of 1975.
The 5 South Dakota counties nearest Lawrence County in number of bridges, with their condition splits. Its 12.5% Poor share is the 2nd-lowest of these 6. Its average build year of 1980 against a peer-group mean of 1971 is 9 years newer.
Showing the 5 closest of 65 South Dakota counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Butte County | 143 | 30.8% | 57.3% | 11.9% | 1976 |
| Turner County | 143 | 38.5% | 35.7% | 25.9% | 1984 |
| Lawrence County (this page) | 136 | 36% | 51.5% | 12.5% | 1980 |
| Bon Homme County | 126 | 21.4% | 50.8% | 27.8% | 1961 |
| Hand County | 126 | 24.6% | 46% | 29.4% | 1961 |
| Davison County | 123 | 34.1% | 48.8% | 17.1% | 1973 |
Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Lawrence County's. Source: FHWA National Bridge Inventory, 2024 release.
Two NBI-derived peer sets for Lawrence County, both outside South Dakota so the neighborhoods are not the same-state size table above.
Nearest county inventories outside SD (136 bridges here).
Nearest mean year-built outside SD (1980 here).
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Over: FALSE BOTTOM CREEK
T 5 N R 2 E SEC 24, Lawrence, SD
Over: FALSE BOTTOM CREEK
T 5 N R 2 E SEC 24, Lawrence, SD
Over: CROW CK
7.1W 2.8N SPEARFISH, Lawrence, SD
Over: HIGGINS GULCH
0.5N SPEARFISH, Lawrence, SD
Over: WHITEWOOD CK
0.7E Int. SD 14A, Lawrence, SD
Over: FALSE BOTTOM CK
2.2 MI N & 1.2 W ST ONGE, Lawrence, SD
Over: BOXELDER CK
AT NEMO, Lawrence, SD
Over: WHITEWOOD CK
MCKINLEY ST - DEADWOOD, Lawrence, SD
Over: ESTES CK
1.6 S 0.6 E NEMO, Lawrence, SD
Over: SPEARFISH CK
0.2 W JCT US 85, Lawrence, SD
Over: SPEARFISH CK
1.5 W 5.5 N SPEARFIS, Lawrence, SD
Over: CARLSON DITCH
Tumbleweed Tl-Spearfish, Lawrence, SD
Over: I090
SPEARFISH INTERCHANGE, Lawrence, SD
Over: WHITEWOOD CK
RODEO ENTR. - DEADWOOD, Lawrence, SD
Over: BEAVER CK
6.5 W 1 N SPEARFISH, Lawrence, SD
Over: SPEARFISH CK
1.5S Savoy, Lawrence, SD
Over: BOXELDER CREEK
T 3 N R 5 E SEC 28, Lawrence, SD
Over: BOULDER CK
3.2 NE JCT 85/14A, Lawrence, SD
Over: REDWATER RV
2E 5.5N SPEARFISH, Lawrence, SD
Over: REDWATER RV
4.5N 2W SPEARFISH, Lawrence, SD
Over: WHITEWOOD CK
0.5 S OF PLUMA, Lawrence, SD
Over: TRIB TO SPEARFISH CK
1.5 W 4.2 N SPEARFISH, Lawrence, SD
Over: I090
US 14A INTERCHANGE, Lawrence, SD
Over: CK
1.0E 0.5S LEAD, Lawrence, SD
Over: POLO CK
0.9E JCT US85S -SPEARFISH, Lawrence, SD
Over: SPEARFISH CK
4.8 N CHEYENNE XING, Lawrence, SD
Over: SANDSTONE DR
0.7 W US 14A INTERCH, Lawrence, SD
Over: BOXELDER CREEK
T 3 N R 5 E SEC 29, Lawrence, SD
Over: CK
3.7 SE BUTTE CO LINE, Lawrence, SD
Over: FALSE BOTTOM CK
2.6 S ST. ONGE, Lawrence, SD
Over: FALSE BOTTOM CK
0.1W 1.3S. ST. ONGE, Lawrence, SD
Over: REDWATER RV
BUTTE CO LINE, Lawrence, SD
Over: BEAR BUTTE CK
2.9 W I 90 INTERCH, Lawrence, SD
Over: N RAINBOW RD
1.5 W US 85 S INTERCH, Lawrence, SD
Over: REDWATER RV
0.5W 7.0N SPEARFISH, Lawrence, SD
Over: WHITEWOOD CK
0.9N 0.6E WHITEWOOD, Lawrence, SD
Over: DEADWOOD CK
2 N JCT US 85, Lawrence, SD
Over: HIGGINS GULCH
.9N 2.7W SPEARFISH, Lawrence, SD
Over: FALSE BOTTOM CK
1 E US 14A INTERCH, Lawrence, SD
Over: FALSE BOTTOM CK
1 E US 14A INTERCH, Lawrence, SD
Over: DEADWOOD CK
CENTRAL CITY, Lawrence, SD
Over: CK
0.7 W I 90 INTERCH, Lawrence, SD
Over: CHIPMUNK GULCH
ST JOE ST SPEARFISH, Lawrence, SD
Over: WEST STRAWBERRY CK
0.6 S OF PLUMA, Lawrence, SD
Over: CK
2.0 W & S I 90 INTERCH, Lawrence, SD
Over: CK
1.2 W I 90 INTERCH, Lawrence, SD
Over: BEAR BUTTE CK
6.2 S OF PLUMA, Lawrence, SD
Over: MIDDLE BOX ELDER CK
5.8 N PENNINGTON CO LINE, Lawrence, SD
Over: DRAW
4.2 SW JCT 90/14A, Lawrence, SD
Read our methodology - how this data is sourced, computed, and verified.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.