US Bridges

US 287 over Grayling Creek

Fair

Gallatin County, Montana · 10M NW West Yellowstone · Structure no. P00087020+02541

Built
1964
61 years old
Condition
Fair
inspected August 2024
Type
Slab
Prestressed Concrete
Length
76 ft
3 main spans
Daily traffic
1,132
2023 count
Owner
State
State Highway Agency

About this bridge

US 287 over Grayling Creek is a prestressed concrete slab carrying US 287 over Grayling Creek in Gallatin County, Montana. It was built in 1964, so it is 61 years old, older than the Montana average of 47 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.

It carries about 1,132 vehicles a day, roughly 3% of them trucks, projected to reach 1,245 by 2043. The structure is 76 ft (23.2 m) long and 31 ft wide. If it were closed, the detour would be 54.1 mi (87 km).

Location

Open in Google Maps
CarriesUS 287
CrossesGrayling Creek
Location10M NW West Yellowstone
RouteU.S. Route 287
CountyGallatin County
StateMontana
Coordinates44.79621, -111.15278
Functional classRural Minor Arterial

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.
Superstructure7 GoodSome minor problems.
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 inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47 US tons
Inventory rating35.1 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans3
Design loadHS 20
Structure length76 ft (23.2 m)
Longest span25 ft (7.6 m)
Deck width31 ft (9.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,132 (2023)
Projected traffic1,245 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed54.1 mi (87 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 287 over Grayling Creek built?

It was built in 1964, making it 61 years old in 2025.

What condition is US 287 over Grayling 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 2024.

How much traffic does US 287 over Grayling Creek carry?

About 1,132 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is US 287 over Grayling Creek?

The structure is 76 ft (23.2 m) long with a longest span of 25 ft (7.6 m) and a deck 31 ft wide.

Who owns US 287 over Grayling Creek?

It is owned by the State Highway Agency.