US Bridges

Lake Side Drive over Guernsey Dam Spillway

FairPosted for load

Platte County, Wyoming · 1.8 Miles NW of Guernsey · Structure no. WYA-NPP-001

Built
1927
98 years old
Condition
Fair
inspected November 2023
Type
Tee Beam
Concrete
Length
79 ft
1 main span
Daily traffic
100
2011 count
Owner
Federal
Bureau of Reclamation

About this bridge

Lake Side Drive over Guernsey Dam Spillway is a concrete tee beam carrying Lake Side Drive over Guernsey Dam Spillway in Platte County, Wyoming. It was built in 1927, so it is 98 years old, older than the Wyoming average of 48.4 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 100 vehicles a day, projected to reach 110 by 2041. The structure is 79 ft (24 m) long and 20 ft wide. If it were closed, the detour would be 18 mi (29 km).

Location

Open in Google Maps
CarriesLake Side Drive
CrossesGuernsey Dam Spillway
Location1.8 Miles NW of Guernsey
RouteState Highway 317
CountyPlatte County
StateWyoming
Coordinates42.29083, -104.76444
Functional classRural Minor Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 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 geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating9.9 US tons
Inventory rating6 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadUnknown
Structure length79 ft (24 m)
Longest span52 ft (15.8 m)
Deck width20 ft (6.2 m)
Roadway width15 ft (4.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2011)
Projected traffic110 by 2041
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed18 mi (29 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerBureau of Reclamation
Maintained byBureau of Reclamation
Historic statusListed on the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Lake Side Drive over Guernsey Dam Spillway built?

It was built in 1927, making it 98 years old in 2025.

What condition is Lake Side Drive over Guernsey Dam Spillway 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 November 2023.

How much traffic does Lake Side Drive over Guernsey Dam Spillway carry?

About 100 vehicles per day (2011 count).

How long is Lake Side Drive over Guernsey Dam Spillway?

The structure is 79 ft (24 m) long with a longest span of 52 ft (15.8 m) and a deck 20 ft wide.

Who owns Lake Side Drive over Guernsey Dam Spillway?

It is owned by the Bureau of Reclamation.