US Bridges

US 30 over Natural Creek

Good

Harrison County, Iowa · 0.4 Mi. E. of S.R. L-34 · Structure no. 000000000027440

Built
1929
96 years old
Condition
Good
inspected July 2023
Type
Culvert
Concrete
Length
40 ft
1 main span
Daily traffic
4,790
2022 count
Owner
State
State Highway Agency

About this bridge

US 30 over Natural Creek is a concrete culvert carrying US 30 over Natural Creek in Harrison County, Iowa. It was built in 1929, so it is 96 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 4,790 vehicles a day, roughly 23% of them trucks, projected to reach 4,790 by 2043. The structure is 40 ft (12.2 m) long. If it were closed, the detour would be 39.1 mi (63 km).

Location

Open in Google Maps
CarriesUS 30
CrossesNatural Creek
Location0.4 Mi. E. of S.R. L-34
RouteU.S. Route 30
CountyHarrison County
StateIowa
Coordinates41.64353, -95.77251
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating48 US tons
Inventory rating36 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans1
Design loadHS 20
Structure length40 ft (12.2 m)
Longest span40 ft (12.2 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,790 (2022)
Projected traffic4,790 by 2043
Trucks23%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed39.1 mi (63 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 30 over Natural Creek built?

It was built in 1929, making it 96 years old in 2025.

What condition is US 30 over Natural Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2023.

How much traffic does US 30 over Natural Creek carry?

About 4,790 vehicles per day (2022 count), of which roughly 23% are trucks.

How long is US 30 over Natural Creek?

The structure is 40 ft (12.2 m) long with a longest span of 40 ft (12.2 m).

Who owns US 30 over Natural Creek?

It is owned by the State Highway Agency.