Total bridges
108
Public highway bridges in Lassen County
County profile · official public datasets
Lassen County, CA
108 public highway bridges tracked in the FHWA National Bridge Inventory: 25.9% rated Good, 65.7% Fair, 8.3% Poor.
- 108
- Public bridges
- 25.9%
- Good condition
- 8.3%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Lassen County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 40th
- of 58 on Poor share
- 8.3%
- Poor-condition share
- 108
- public highway bridges
- 1968
- 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.
Lassen County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Lassen County ranks #40 of 58 California counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.3%). Lassen County, California contains 108 public highway bridges. Roughly 25.9% are rated “Good,” 65.7% “Fair,” and 8.3% “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
25.9%
28 of 108 rated 7-9
Fair condition
65.7%
71 of 108 rated 5-6
Poor condition
8.3%
9 of 108 rated 4 or below
In-state Poor-share rank
#40 of 58
Among California counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 108 NBI-tracked bridges by lowest applicable component rating.
Good 25.9% (28)
Fair 65.7% (71)
Poor 8.3% (9)
Lassen County's Poor-condition bridges carry 2,482 vehicle crossings a day
That is 1.4% of the county's reported daily bridge traffic on 8.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 276 crossings a day against 2,480 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 108 of 108 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
53.7% of Lassen County's bridges have passed the 50-year mark
58 of the 108 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 25.9% 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 60.4% of the county's Poor-condition bridge traffic
CR A21 / MOONEY RD over ROBBERS CREEK, built 1975, carries 1,500 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 9-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 2,482 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Lassen County's bridges were built
108 bridges with a recorded construction year, grouped by decade
- 1920s
1920–1929
15 bridges
- 1930s 5
1930–1939
5 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s 9
1950–1959
9 bridges
- 1960s
1960–1969
20 bridges
- 1970s
1970–1979
34 bridges
- 1980s 7
1980–1989
7 bridges
- 1990s 5
1990–1999
5 bridges
- 2000s 3
2000–2009
3 bridges
- 2010s 5
2010–2019
5 bridges
- 2020s 3
2020–2029
3 bridges
What this shows Construction peaked in the 1970s, when 34 of the county's bridges still in the inventory were built, which is 31.5% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1968) matches the California average (1970).
How Lassen County compares with California's closest counties by inventory size
The 5 California counties nearest Lassen County in number of bridges, with their condition splits. Its 8.3% Poor share is the 3rd-lowest of these 6. Its average build year of 1968 against a peer-group mean of 1965 is in line with the group.
Showing the 5 closest of 57 California counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Tuolumne County | 125 | 36% | 56.8% | 7.2% | 1964 |
| Sutter County | 121 | 33.9% | 52.9% | 13.2% | 1968 |
| Mariposa County | 109 | 21.1% | 67.9% | 11% | 1956 |
| Lassen County (this page) | 108 | 25.9% | 65.7% | 8.3% | 1968 |
| Calaveras County | 105 | 33.3% | 60% | 6.7% | 1962 |
| Del Norte County | 96 | 51% | 37.5% | 11.5% | 1975 |
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 Lassen 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 Lassen County, both outside California so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside CA (108 bridges here).
- Pulaski County, IL · 108 bridges
- West Feliciana County, LA · 108 bridges
- Brown County, MN · 108 bridges
- Shelby County, MO · 108 bridges
Similar average build year
Nearest mean year-built outside CA (1968 here).
- Montgomery County, PA · avg 1968 · 828 bridges
- Providence County, RI · avg 1968 · 476 bridges
- Delaware County, PA · avg 1968 · 387 bridges
- Genesee County, MI · avg 1968 · 371 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (108)
RICHMOND ROAD
FairOver: SUSAN RIVER
JUST N. OF RIVERSIDE DR., Lassen, CA
Built 1995 Load: 32.4 t ADT: 3,300
ALEXANDER AVE
FairOver: SUSAN RIVER
0.22 MI S OF S.H. 36, Lassen, CA
Built 1986 Load: 32.4 t ADT: 4,850
ON COUNTY ROAD 320
FairOver: SKEDADDLE CREEK
19.9 MI S/E OF US 395, Lassen, CA
Built 1988 Load: 32.4 t ADT: 200
CR312-BLICKENSTAFF
FairOver: DEEP CUT (BAXTER) CREEK
2.0 MI NE OF ROUTE 395, Lassen, CA
Built 2002 Load: 32.4 t ADT: 130
LEAVITT LN (CR213)
FairOver: SUSAN RIVER OVERFLOW
0.1 MI N OF US 395, Lassen, CA
Built 2009 Load: 32.4 t ADT: 1,500
MAPES LANE RD 305
FairOver: SUSAN RIVER OVERFLOW # 3
3.1 MI E OF LAMBERT LANE, Lassen, CA
Built 2016 Load: 32.4 t ADT: 130
MAPES LANE RD 305
FairOver: SUSAN RIVER OVERFLOW # 5
3.3 MI E OF LAMBERT LANE, Lassen, CA
Built 2016 Load: 32.4 t ADT: 130
HACKSTAFF ROAD
FairOver: LONG VALLEY CREEK
0.4 MI NE OF CR 361, Lassen, CA
Built 2021 Load: 32.4 t ADT: 80
U.S. HIGHWAY 395
FairOver: STATE ROUTE 70
02-LAS-395-R4.60, Lassen, CA
Built 1976 Load: 35.3 t ADT: 4,600
CR316 (MCCLELLAND)
FairOver: NORTH FORK DILL SLOUGH
0.2 MI N OF CR 304, Lassen, CA
Built 1978 Load: 35.3 t ADT: 50
U.S. HIGHWAY 395
FairOver: GALEPPI UC
02-LAS-395-R17.51, Lassen, CA
Built 1969 Load: 36.3 t ADT: 5,500
STATE ROUTE 36
FairOver: SUSAN RIVER
02-LAS-036-R17.38, Lassen, CA
Built 1966 Load: 37.6 t ADT: 2,900
LASSEN ST
FairOver: SUSAN RIVER
0.3 MI S OF S.H. 36, Lassen, CA
Built 1965 Load: 37.9 t ADT: 400
JOHNSTONVILLE RD
FairOver: SUSAN RIVER
0.3 MI N OF US 395, Lassen, CA
Built 1921 Load: 38.2 t ADT: 600
STATE ROUTE 36
FairOver: ROBBERS CREEK
02-LAS-036-3.15, Lassen, CA
Built 1924 Load: 40.2 t ADT: 2,300
U.S. HIGHWAY 395
FairOver: LONG VALLEY CREEK OVFL
02-LAS-395-R21.34, Lassen, CA
Built 1969 Load: 41.1 t ADT: 5,500
CHAPPIUS LANE
FairOver: SUSAN RIVER
1.5 MI N OF SH 395, Lassen, CA
Built 1986 Load: 42.8 t ADT: 300
U.S. HIGHWAY 395
FairOver: WILLOW RANCH CREEK
02-LAS-395-R24.69, Lassen, CA
Built 1969 Load: 44.4 t ADT: 5,500
U.S. HIGHWAY 395
FairOver: EVANS CANYON RD
02-LAS-395-R0.10, Lassen, CA
Built 1976 Load: 50.2 t ADT: 4,600
U.S. HIGHWAY 395
FairOver: EVANS CANYON RD
02-LAS-395-R0.10, Lassen, CA
Built 1976 Load: 52.2 t ADT: 4,600
MAPES LANE RD 305
FairOver: SUSAN RIVER OVERFLOW #4
1.3 MI E OF RD 304, Lassen, CA
Built 2000 Load: 56.1 t ADT: 100
NO DATA ENTERED
GoodOver: PINE CREEK
NO DATA ENTERED, Lassen, CA
Built 1961 ADT: 20
PARK RIVERSIDE DR
GoodOver: SUSAN RIVER
0.6 MI E ALEXANDER DR, Lassen, CA
Built 1973 Load: 13.0 t ADT: 4,500
U.S. HIGHWAY 395
GoodOver: STANDISH IRRIG. CANAL
02-LAS-395-62.19, Lassen, CA
Built 1936 Load: 24.3 t ADT: 2,975
STATE ROUTE 299
GoodOver: RAINES CREEK
02-LAS-299-2.45, Lassen, CA
Built 1931 Load: 24.3 t ADT: 1,500
STATE ROUTE 299
GoodOver: BIEBER CREEK
02-LAS-299-19.83, Lassen, CA
Built 1928 Load: 24.3 t ADT: 1,050
STATE ROUTE 299
GoodOver: WILLOW CREEK
02-LAS-299-24.01, Lassen, CA
Built 1929 Load: 24.3 t ADT: 1,050
HERLONG ACCESS RD
GoodOver: LONG VALLEY CREEK
2.2 MI E US HWY 395, Lassen, CA
Built 1979 Load: 27.9 t ADT: 800
STATE ROUTE 299
GoodOver: BNSF RY
02-LAS-299-11.89, Lassen, CA
Built 1977 Load: 29.5 t ADT: 1,800
U.S. HIGHWAY 395
GoodOver: SUSAN RIVER
02-LAS-395-72.29, Lassen, CA
Built 1954 Load: 30.8 t ADT: 1,775
U.S. HIGHWAY 395
GoodOver: LONG VALLEY CREEK
02-LAS-395-26.19, Lassen, CA
Built 1946 Load: 32.4 t ADT: 5,500
STATE ROUTE 36
GoodOver: JENSEN SLOUGH
02-LAS-036-R26.36, Lassen, CA
Built 1964 Load: 32.4 t ADT: 15,300
STATE ROUTE 36
GoodOver: GOLD RUN CREEK
02-LAS-036-R27.36, Lassen, CA
Built 1964 Load: 32.4 t ADT: 10,300
STATE ROUTE 36
GoodOver: GOODRICH CREEK
02-LAS-036-7.30, Lassen, CA
Built 2021 Load: 32.4 t ADT: 2,300
MCCOY RD
GoodOver: SUSAN RIVER
1.6 MI S OF SR 44, Lassen, CA
Built 1989 Load: 32.4 t ADT: 100
COUNTY RD 311
GoodOver: DEEP CUT (BAXTER) CREEK
1.75 MI E OF CR A 3, Lassen, CA
Built 1988 Load: 32.4 t ADT: 150
CR 518 (SPALDING)
GoodOver: PINE CREEK
1.5 MI S EAGLE LAKE RD, Lassen, CA
Built 1976 Load: 32.4 t ADT: 1,800
ARMSTRONG ROAD
GoodOver: WILLOW CREEK
0.25 MI. S. OF SUSANV. RD, Lassen, CA
Built 1995 Load: 32.4 t ADT: 50
SKYLINE ROAD
GoodOver: SUSAN RIVER
0.15 MILE NE OF US 395, Lassen, CA
Built 2019 Load: 32.4 t ADT: 2,000
HACKSTAFF ROAD
GoodOver: LONG VALLEY CREEK
0.6 MI NE OF CR 361, Lassen, CA
Built 2021 Load: 32.4 t ADT: 80
STATE ROUTE 139
GoodOver: WILLOW CREEK
02-LAS-139-17.02, Lassen, CA
Built 1966 Load: 33.0 t ADT: 550
CONSERVATION CTR R
GoodOver: BROCKMAN SLOUGH
7.5 MI E OF SR 36, Lassen, CA
Built 1969 Load: 36.3 t ADT: 1,200
U.S. HIGHWAY 395
GoodOver: STATE ROUTE 70
02-LAS-395-R4.60, Lassen, CA
Built 1976 Load: 38.2 t ADT: 4,600
STATE ROUTE 139
GoodOver: MEADOW CHANNEL
02-LAS-139-16.92, Lassen, CA
Built 1966 Load: 41.1 t ADT: 550
BERT ROAD
GoodOver: LONG VALLEY CRK OVRFLOW
0.6 MI S OF US HWY 395, Lassen, CA
Built 1968 Load: 41.1 t ADT: 10
CR302 (LAMBERT LN)
GoodOver: HARTSON SLOUGH
0.4 MI SOUTH OF US 395, Lassen, CA
Built 2011 Load: 50.5 t ADT: 166
RD 302 (LAMBERT)
GoodOver: HARTSON SLOUGH OVERFLOW
0.3 MI SOUTH OF US 395, Lassen, CA
Built 2011 Load: 50.5 t ADT: 100
U.S. HIGHWAY 395
GoodOver: SCOTT UC
02-LAS-395-R1.09, Lassen, CA
Built 1976 Load: 52.2 t ADT: 4,600
U.S. HIGHWAY 395
GoodOver: SCOTT UC
02-LAS-395-R1.09, Lassen, CA
Built 1976 Load: 53.8 t ADT: 4,600
CR 305 (MAPES RD)
PoorOver: HARTSON SLOUGH
0.4 MI E/O RD 303, Lassen, CA
Built 1978 Load: 0.0 t ADT: 100
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.