Total bridges
559
Public highway bridges in Larimer County
County profile · official public datasets
559 public highway bridges tracked in the FHWA National Bridge Inventory: 49% rated Good, 49% Fair, 2% Poor.
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Larimer County pairs a top-quartile lowest 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, Larimer County ranks #16 of 64 Colorado counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2%). Larimer County, Colorado contains 559 public highway bridges. Roughly 49% are rated “Good,” 49% “Fair,” and 2% “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
559
Public highway bridges in Larimer County
Good condition
49%
274 of 559 rated 7-9
Fair condition
49%
274 of 559 rated 5-6
Poor condition
2%
11 of 559 rated 4 or below
In-state Poor-share rank
#16 of 64
Among Colorado counties with 5+ bridges, lower share ranks better
Share of 559 NBI-tracked bridges by lowest applicable component rating.
That is 1.4% of the county's reported daily bridge traffic on 2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 5,203 crossings a day against 8,152 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 557 of 559 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
161 of the 559 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 49% 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.
SH 392 ML over CACHE LA POUDRE RIVER, built 1959, carries 19,000 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 11-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 57,230 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
559 bridges with a recorded construction year, grouped by decade
1900–1909
1 bridges
1910–1919
2 bridges
1920–1929
7 bridges
1930–1939
19 bridges
1940–1949
12 bridges
1950–1959
29 bridges
1960–1969
76 bridges
1970–1979
48 bridges
1980–1989
102 bridges
1990–1999
58 bridges
2000–2009
78 bridges
2010–2019
99 bridges
2020–2029
28 bridges
What this shows Construction peaked in the 1980s, when 102 of the county's bridges still in the inventory were built, which is 18.2% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1987, 5 years newer than the Colorado average of 1982.
The 5 Colorado counties nearest Larimer County in number of bridges, with their condition splits. Its 2% Poor share is the 2nd-lowest of these 6. Its average build year of 1987 against a peer-group mean of 1987 is in line with the group.
Showing the 5 closest of 63 Colorado counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| El Paso County | 686 | 31.3% | 65.5% | 3.2% | 1984 |
| Weld County | 614 | 36.8% | 58.5% | 4.7% | 1986 |
| Larimer County (this page) | 559 | 49% | 49% | 2% | 1987 |
| Adams County | 535 | 43.9% | 49.2% | 6.9% | 1990 |
| Jefferson County | 464 | 33.8% | 59.9% | 6.3% | 1984 |
| Denver County | 458 | 41.9% | 56.3% | 1.7% | 1991 |
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 Larimer County's. Source: FHWA National Bridge Inventory, 2024 release.
Two NBI-derived peer sets for Larimer County, both outside Colorado so the neighborhoods are not the same-state size table above.
Nearest county inventories outside CO (559 bridges here).
Nearest mean year-built outside CO (1987 here).
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Over: Little Thompson River
0.7 Mi N of S County Line, Larimer, CO
Over: Little Thompson River
0.1 Mi N of Co Rd 45B, Larimer, CO
Over: Big Thompson River
0.2 Mi N of 1st Street, Larimer, CO
Over: N Frk Cache La Poudre Rv
2.6 Mi W of Co Rd 59, Larimer, CO
Over: Boxelder Creek
0.8 Mi N of Co Rd 78, Larimer, CO
Over: Rawhide Creek
0.2 Mi E of Co Rd 15, Larimer, CO
Over: Cache La Poudre River
0.2 Mi N of Co Rd 50E, Larimer, CO
Over: BIG THOMPSON RIVER
1.9 MILES SOUTH OF BEAVER, Larimer, CO
Over: Coal Creek
0.3 Mi E of Co Rd 7, Larimer, CO
Over: Larimer County Canal
0.9 Mi E of Co Rd 11, Larimer, CO
Over: N Frk Cache La Poudre Rv
1.0 Mi E of Co Rd 37, Larimer, CO
Over: Cache La Poudre River
75 Ft S of St Hwy 14, Larimer, CO
Over: Big Thompson River
25 Ft S of US Hwy 34, Larimer, CO
Over: Big Thompson River
0.2 Mi N of US Hwy 34, Larimer, CO
Over: Lone Pine Creek
0.2 Mi N of Co Rd 74E, Larimer, CO
Over: Cache La Poudre River
0.4 Mi S of St Hwy 392, Larimer, CO
Over: LOUDEN CANAL
3.5 MI N OF JCT US 34, Larimer, CO
Over: Big Thompson River
20 Ft S of US Hwy 34, Larimer, CO
Over: Big Thompson River
40 Ft S of US Hwy 34, Larimer, CO
Over: Big Thompson River
35 Ft S of US Hwy 34, Larimer, CO
Over: LARIMER-WELD CANAL
0.2 MI S of SH1, Larimer, CO
Over: Larimer & Weld Canal
1.2 Mi East of I-25, Larimer, CO
Over: Mail Creek
100 ft S of W Co. Rd 38, Larimer, CO
Over: Little Thompson River
50 ft S of W CR 4, Larimer, CO
Over: CACHE LA POUDRE RIVER
50 FT SOUTH OF CO HWY 114, Larimer, CO
Over: North Poudre Canal
1.5 Mi N of Co Rd 70, Larimer, CO
Over: FALL RIVER
0.2 MILES FROM FALL RIVER, Larimer, CO
Over: N Frk Cache La Poudre Rv
0.5 Mi E of Co Rd 37, Larimer, CO
Over: Big Thompson River
15 Ft S of US Hwy 34, Larimer, CO
Over: N.POUDRE DITCH SAND CRK
11.6 MI NORTH OF JCT SH 1, Larimer, CO
Over: DRAW
3.8 MI W OF LOVELAND, Larimer, CO
Over: Pleas Valley Lake Canal
1.3 Mi N of Co Rd 52E, Larimer, CO
Over: Pleas. Valley Lake Canal
0.7 Mi E of Co Rd 27E, Larimer, CO
Over: Larimer County Canal
1.1 Mi E of I-25, Larimer, CO
Over: Larimer Poudre Canal
6.8 Mi N of St Hwy 14, Larimer, CO
Over: Poudre Valley Canal
50 Ft N of Co Rd 64, Larimer, CO
Over: LOUDEN CANAL
3.2 MI N OF JCT US 34, Larimer, CO
Over: SIX MILE CREEK
21.5 MILES NORTH OF TEDS, Larimer, CO
Over: Jackson Ditch
0.2 Mi No of Co Rd 52C, Larimer, CO
Over: Cache La Poudre River
0.1 Mi E of Co Rd 3, Larimer, CO
Over: Larimer & Weld Canal
0.8 Mi East of I-25, Larimer, CO
Over: LARIMER COUNTY CANAL
FT COLLINS, Larimer, CO
Over: YOUNGS GULCH
13 MI EAST OF ROAD TO EGG, Larimer, CO
Over: South Lone Pine Creek
9.9 Mi E of Co Rd 68C, Larimer, CO
Over: Cache La Poudre River
Just S of CR14, Larimer, CO
Over: BIG THOMPSON RIVER
0.4 MI N OF JCT SH 402, Larimer, CO
Over: LARAMIE POUDRE CANAL
0.1 MI N OF JCT SH 14, Larimer, CO
Over: N Frk Cache La Poudre Rv
1.9 MIi E of Co Rd 37, Larimer, CO
Over: DITCH
1.2 MI S OF TEDS PLACE, Larimer, CO
Over: HANDY DITCH
3.7 MI WEST OF LOVELAND, Larimer, CO
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.