US Bridges

Nelson RD over Beaver Creek 121

Fair

Lewis and Clark County, Montana · Nelson · Structure no. L25103007+08001

Built
1975
50 years old
Condition
Fair
inspected August 2023
Type
Channel Beam
Prestressed Concrete
Length
27 ft
1 main span
Daily traffic
234
2023 count
Owner
County
County Highway Agency

About this bridge

Nelson RD over Beaver Creek 121 is a prestressed concrete channel beam carrying Nelson RD over Beaver Creek 121 in Lewis and Clark County, Montana. It was built in 1975, so it is 50 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 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 234 vehicles a day, roughly 3% of them trucks, projected to reach 247 by 2043. The structure is 27 ft (8.2 m) long and 23 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesNelson RD
CrossesBeaver Creek 121
LocationNelson
RouteCounty Highway 25103
CountyLewis and Clark County
StateMontana
Coordinates46.81484, -111.81028
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating38.1 US tons
Inventory rating26.9 US tons

Structure

Structure typeChannel Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length27 ft (8.2 m)
Longest span24 ft (7.3 m)
Deck width23 ft (6.9 m)
Roadway width21 ft (6.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic234 (2023)
Projected traffic247 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 Nelson RD over Beaver Creek 121 built?

It was built in 1975, making it 50 years old in 2025.

What condition is Nelson RD over Beaver Creek 121 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 2023.

How much traffic does Nelson RD over Beaver Creek 121 carry?

About 234 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Nelson RD over Beaver Creek 121?

The structure is 27 ft (8.2 m) long with a longest span of 24 ft (7.3 m) and a deck 23 ft wide.

Who owns Nelson RD over Beaver Creek 121?

It is owned by the County Highway Agency.