US Bridges

Stc 5804;WESTSIDE over Myrtle Creek

Poor

Boundary County, Idaho · 0.8N. 4.8W. Bonners Ferry · Structure no. 000000000020695

Built
1958
67 years old
Condition
Poor
inspected July 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
52 ft
1 main span
Daily traffic
300
2023 count
Owner
County
County Highway Agency

About this bridge

Stc 5804;WESTSIDE over Myrtle Creek is a wood or timber stringer/multi-beam or girder carrying Stc 5804;WESTSIDE over Myrtle Creek in Boundary County, Idaho. It was built in 1958, so it is 67 years old, older than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 300 vehicles a day, roughly 7% of them trucks, projected to reach 450 by 2042. The structure is 52 ft (15.8 m) long and 19 ft wide. If it were closed, the detour would be 37.9 mi (61 km).

CarriesStc 5804;WESTSIDE
CrossesMyrtle Creek
Location0.8N. 4.8W. Bonners Ferry
RouteCounty Highway 5804
StateIdaho
Coordinates48.70786, -116.4165
Functional classRural Major Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating41 US tons
Inventory rating26 US tons

Structure

MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length52 ft (15.8 m)
Longest span50 ft (15.2 m)
Deck width19 ft (5.8 m)
Roadway width18 ft (5.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic300 (2023)
Projected traffic450 by 2042
Trucks7%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed37.9 mi (61 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$502,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Stc 5804;WESTSIDE over Myrtle Creek built?

It was built in 1958, making it 67 years old in 2025.

What condition is Stc 5804;WESTSIDE over Myrtle Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in July 2024.

How much traffic does Stc 5804;WESTSIDE over Myrtle Creek carry?

About 300 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is Stc 5804;WESTSIDE over Myrtle Creek?

The structure is 52 ft (15.8 m) long with a longest span of 50 ft (15.2 m) and a deck 19 ft wide.

Who owns Stc 5804;WESTSIDE over Myrtle Creek?

It is owned by the County Highway Agency.