US Bridges

Mill Crossing over Lagunitas Creek

FairPosted for load

Marin County, California · Samuel P Taylor State Pk · Structure no. 27P0002

Built
1947
78 years old
Condition
Fair
inspected August 2023
Type
Truss - Deck
Steel
Length
112 ft
1 main span
Daily traffic
1
1998 count
Owner
State
State Park, Forest, or Reservation Agency

About this bridge

Mill Crossing over Lagunitas Creek is a steel truss - deck carrying Mill Crossing over Lagunitas Creek in Marin County, California. It was built in 1947, so it is 78 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 1 vehicles a day, projected to reach 1 by 2041. The structure is 112 ft (34.1 m) long and 11 ft wide.

Location

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CarriesMill Crossing
CrossesLagunitas Creek
LocationSamuel P Taylor State Pk
RouteState Lands Road 0
CountyMarin County
StateCalifornia
Coordinates38.02886, -122.74216
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating19.3 US tons
Inventory rating11.5 US tons

Structure

Structure typeTruss - Deck
MaterialSteel
DeckWood or timber
Main spans1 (+2 approach)
Design loadUnknown
Structure length112 ft (34.1 m)
Longest span72 ft (21.9 m)
Deck width11 ft (3.5 m)
Roadway width10 ft (3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1 (1998)
Projected traffic1 by 2041
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Park, Forest, or Reservation Agency
Maintained byState Park, Forest, or Reservation Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Mill Crossing over Lagunitas Creek built?

It was built in 1947, making it 78 years old in 2025.

What condition is Mill Crossing over Lagunitas Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in August 2023.

How much traffic does Mill Crossing over Lagunitas Creek carry?

About 1 vehicles per day (1998 count).

How long is Mill Crossing over Lagunitas Creek?

The structure is 112 ft (34.1 m) long with a longest span of 72 ft (21.9 m) and a deck 11 ft wide.

Who owns Mill Crossing over Lagunitas Creek?

It is owned by the State Park, Forest, or Reservation Agency.