US Bridges

Moon Lake Road over Farnsworth Canal

Fair

Duchesne County, Utah · 11.5 MI N Mt Home Utah · Structure no. 040103000001019

Built
1963
62 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
28 ft
1 main span
Daily traffic
200
2018 count
Owner
Federal
U.S. Forest Service

About this bridge

Moon Lake Road over Farnsworth Canal is a wood or timber stringer/multi-beam or girder carrying Moon Lake Road over Farnsworth Canal in Duchesne County, Utah. It was built in 1963, so it is 62 years old, older than the Utah average of 40.1 years.

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

It carries about 200 vehicles a day, roughly 10% of them trucks, projected to reach 25 by 2010. The structure is 28 ft (8.5 m) long and 26 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

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CarriesMoon Lake Road
CrossesFarnsworth Canal
Location11.5 MI N Mt Home Utah
RouteFederal Lands Road 10131
CountyDuchesne County
StateUtah
Coordinates40.53555, -110.46769
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating40 US tons
Inventory rating30.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadH 20
Structure length28 ft (8.5 m)
Longest span27 ft (8.2 m)
Deck width26 ft (8 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic200 (2018)
Projected traffic25 by 2010
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.2 mi (158 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Moon Lake Road over Farnsworth Canal built?

It was built in 1963, making it 62 years old in 2025.

What condition is Moon Lake Road over Farnsworth Canal 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 June 2023.

How much traffic does Moon Lake Road over Farnsworth Canal carry?

About 200 vehicles per day (2018 count), of which roughly 10% are trucks.

How long is Moon Lake Road over Farnsworth Canal?

The structure is 28 ft (8.5 m) long with a longest span of 27 ft (8.2 m) and a deck 26 ft wide.

Who owns Moon Lake Road over Farnsworth Canal?

It is owned by the U.S. Forest Service.