US Bridges

Blackwood RD over Hyalite Creek 052

Fair

Gallatin County, Montana · 4M SW Bozeman · Structure no. L16739003+04001

Built
1971
54 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
31 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Blackwood RD over Hyalite Creek 052 is a wood or timber stringer/multi-beam or girder carrying Blackwood RD over Hyalite Creek 052 in Gallatin County, Montana. It was built in 1971, so it is 54 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 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 31 ft (9.4 m) long and 25 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesBlackwood RD
CrossesHyalite Creek 052
Location4M SW Bozeman
RouteCounty Highway 16739
CountyGallatin County
StateMontana
Coordinates45.64177, -111.13137
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionJune 2023
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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43.2 US tons
Inventory rating31.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckCorrugated steel
Main spans1
Design loadUnknown
Structure length31 ft (9.4 m)
Longest span29 ft (8.8 m)
Deck width25 ft (7.6 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2025)
Projected traffic100 by 2040
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Blackwood RD over Hyalite Creek 052 built?

It was built in 1971, making it 54 years old in 2025.

What condition is Blackwood RD over Hyalite Creek 052 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 Blackwood RD over Hyalite Creek 052 carry?

About 100 vehicles per day (2025 count), of which roughly 3% are trucks.

How long is Blackwood RD over Hyalite Creek 052?

The structure is 31 ft (9.4 m) long with a longest span of 29 ft (8.8 m) and a deck 25 ft wide.

Who owns Blackwood RD over Hyalite Creek 052?

It is owned by the County Highway Agency.