US Bridges

SR 189 over Mariposa Canyon

Fair

Santa Cruz County, Arizona · 0.2 MI W JCT I-19 · Structure no. 01797

Built
1977
48 years old, rebuilt 2020
Condition
Fair
inspected May 2024
Type
Box Beam or Girders - Single or Spread
Concrete Continuous
Length
207 ft
3 main spans
Daily traffic
18,816
2024 count
Owner
State
State Highway Agency

About this bridge

SR 189 over Mariposa Canyon is a concrete continuous box beam or girders - single or spread carrying SR 189 over Mariposa Canyon in Santa Cruz County, Arizona. It was built in 1977 and reconstructed in 2020, so it is 48 years old, older than the Arizona average of 47.8 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 18,816 vehicles a day, roughly 14% of them trucks, projected to reach 18,826 by 2042. The structure is 207 ft (63.1 m) long and 121 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesSR 189
CrossesMariposa Canyon
Location0.2 MI W JCT I-19
RouteState Highway 189
CountySanta Cruz County
StateArizona
Coordinates31.36467, -110.94663
Functional classUrban Other Principal 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating81 US tons
Inventory rating48 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length207 ft (63.1 m)
Longest span80 ft (24.4 m)
Deck width121 ft (36.9 m)
Roadway width109 ft (33.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,816 (2024)
Projected traffic18,826 by 2042
Trucks14%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes

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 SR 189 over Mariposa Canyon built?

It was built in 1977, making it 48 years old in 2025. It was reconstructed in 2020.

What condition is SR 189 over Mariposa Canyon 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 May 2024.

How much traffic does SR 189 over Mariposa Canyon carry?

About 18,816 vehicles per day (2024 count), of which roughly 14% are trucks.

How long is SR 189 over Mariposa Canyon?

The structure is 207 ft (63.1 m) long with a longest span of 80 ft (24.4 m) and a deck 121 ft wide.

Who owns SR 189 over Mariposa Canyon?

It is owned by the State Highway Agency.