Total bridges
559
Public highway bridges in Larimer County
County profile · official public datasets
Larimer County, CO
559 public highway bridges tracked in the FHWA National Bridge Inventory: 49% rated Good, 49% Fair, 2% Poor.
- 559
- Public bridges
- 49%
- Good condition
- 2%
- Poor condition
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.
- Top 25%
- lowest Poor share in state
- 2%
- Poor-condition share
- 559
- public highway bridges
- 1987
- avg year built
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.
Larimer County Bridge Snapshot
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.
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
Condition distribution
Share of 559 NBI-tracked bridges by lowest applicable component rating.
Good 49% (274)
Fair 49% (274)
Poor 2% (11)
Larimer County's Poor-condition bridges carry 57,230 vehicle crossings a day
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.
28.8% of Larimer County's bridges have passed the 50-year mark
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.
One structure carries 33.2% of the county's Poor-condition bridge traffic
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.
When Larimer County's bridges were built
559 bridges with a recorded construction year, grouped by decade
- 1900s 1
1900–1909
1 bridges
- 1910s 2
1910–1919
2 bridges
- 1920s 7
1920–1929
7 bridges
- 1930s 19
1930–1939
19 bridges
- 1940s 12
1940–1949
12 bridges
- 1950s 29
1950–1959
29 bridges
- 1960s
1960–1969
76 bridges
- 1970s
1970–1979
48 bridges
- 1980s
1980–1989
102 bridges
- 1990s
1990–1999
58 bridges
- 2000s
2000–2009
78 bridges
- 2010s
2010–2019
99 bridges
- 2020s 28
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.
How Larimer County compares with Colorado's closest counties by inventory size
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.
Nationwide counties with similar inventory size or average build year
Two NBI-derived peer sets for Larimer County, both outside Colorado so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside CO (559 bridges here).
- Chautauqua County, NY · 559 bridges
- Yakima County, WA · 558 bridges
- Pottawattamie County, IA · 557 bridges
- Shawnee County, KS · 563 bridges
Similar average build year
Nearest mean year-built outside CO (1987 here).
- St. Louis County, MO · avg 1987 · 912 bridges
- Ellis County, TX · avg 1987 · 691 bridges
- St. Louis County, MN · avg 1987 · 663 bridges
- Palm Beach County, FL · avg 1987 · 610 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (274)
SH 14 ML
FairOver: DRY CREEK
MULBERRY andTIMBERLINE RD, Larimer, CO
Built 1999 Load: 60.5 t ADT: 33,000
I 25 ML
FairOver: LAKE CANAL
11.3 MI N OF JCT SH 34, Larimer, CO
Built 1966 Load: 62.6 t ADT: 55,000
I 25 ML
FairOver: CACHE LA POUDRE DITCH
11.3 MI N OF JCT US 34, Larimer, CO
Built 1966 Load: 63.2 t ADT: 55,000
Timberline Road
FairOver: Spring Creek
100 Ft S of Prospect Rd., Larimer, CO
Built 1986 Load: 66.6 t ADT: 36,342
I 25 ML+SERVICE RD
FairOver: BOX ELDER CREEK
5.1 MI N OF JCT SH 14, Larimer, CO
Built 1989 Load: 66.8 t ADT: 28,000
US 287 ML
FairOver: LAKE DITCH
0.4 MI N of SH60, Larimer, CO
Built 2005 Load: 81.0 t ADT: 20,000
County Road 23E
FairOver: Handy Ditch
0.3 Mi N of Co Rd 18, Larimer, CO
Built 1983 Load: 81.0 t ADT: 1,075
County Road 21C
FairOver: Jackson Ditch
0.4 Mi N of Co Rd 54G, Larimer, CO
Built 1986 Load: 82.0 t ADT: 772
Boardwalk Drive
FairOver: Larimer Co. Canal No. 2
50 Ft N of Troutman Pkwy, Larimer, CO
Built 1982 Load: 84.5 t ADT: 7,952
US 287 ML
FairOver: HANDY DITCH
1 MI. N. OF CO RD 8, Larimer, CO
Built 2003 Load: 89.1 t ADT: 18,000
US 287 ML
FairOver: DRAW
0.1 Mi South of 37th St, Larimer, CO
Built 1924 Load: 89.8 t ADT: 29,000
County Road 21C
FairOver: Larimer Co. Canal No. 2
0.3 Mi N of Co Rd 50, Larimer, CO
Built 1983 Load: 91.2 t ADT: 4,081
County Road 21C
FairOver: New Mercer Canal
0.2 Mi N of Co Rd 50, Larimer, CO
Built 1983 Load: 93.9 t ADT: 4,081
County Road 20
FairOver: Dry Creek
0.3 Mi E of Co Rd 29, Larimer, CO
Built 1982 Load: 96.9 t ADT: 2,122
County Road 72
FairOver: Park Creek
3.4 Mi E of SH287, Larimer, CO
Built 2014 Load: 96.9 t ADT: 4,435
I25 ML+FRONTAGE RD
FairOver: WINDSOR RES CANAL
0.4 MI N OF JCT SH1, Larimer, CO
Built 1989 Load: 99.9 t ADT: 25,000
US 34 ML
FairOver: BUCKINGHAM DITCH
2 MI WEST OF LOVELAND, Larimer, CO
Built 1997 Load: 99.9 t ADT: 8,300
US 34 ML
FairOver: DRAW
AT W. END OF LOVELAND, Larimer, CO
Built 1998 Load: 99.9 t ADT: 8,300
Landing Drive
FairOver: Larimer Co. Canal No. 2
0.1 Mi N of Boardwalk Dr, Larimer, CO
Built 1982 Load: 99.9 t ADT: 2,208
Taft Avenue
FairOver: Greeley Loveland Canal
0.4 Mi N of First St, Larimer, CO
Built 1980 Load: 99.9 t ADT: 21,527
County Road 15
FairOver: Poudre Valley Canal
1.0 Mi N of Co Rd 60, Larimer, CO
Built 1987 Load: 99.9 t ADT: 1,784
County Road 29
FairOver: Green Ridge Glade Reser.
0.3 Mi N of Co Rd 22H, Larimer, CO
Built 2004 Load: 99.9 t ADT: 145
County Road 30
FairOver: Louden Ditch
0.2 Mi E of US Hwy 287, Larimer, CO
Built 1979 Load: 99.9 t ADT: 1,036
County Road 70
FairOver: Coal Creek
0.9 Mi E of Co Rd 9, Larimer, CO
Built 1995 Load: 99.9 t ADT: 6,026
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges
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.