US Bridges

FSR 644 over Rocky Gulch

Fair

Yavapai County, Arizona · 2.4 MI Sw/O Stoneman Lk · Structure no. 030401000004104

Built
1968
57 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
29 ft
1 main span
Daily traffic
75
2021 count
Owner
Federal
U.S. Forest Service

About this bridge

FSR 644 over Rocky Gulch is a wood or timber stringer/multi-beam or girder carrying FSR 644 over Rocky Gulch in Yavapai County, Arizona. It was built in 1968, so it is 57 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 75 vehicles a day, projected to reach 125 by 2040. The structure is 29 ft (8.7 m) long and 15 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

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CarriesFSR 644
CrossesRocky Gulch
Location2.4 MI Sw/O Stoneman Lk
RouteFederal Lands Road 644
CountyYavapai County
StateArizona
Coordinates34.74559, -111.54384
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating32.5 US tons
Inventory rating25 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length29 ft (8.7 m)
Longest span28 ft (8.4 m)
Deck width15 ft (4.7 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic75 (2021)
Projected traffic125 by 2040
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.7 mi (14 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$200,000
NavigationNo navigation control on waterway

Frequently asked questions

When was FSR 644 over Rocky Gulch built?

It was built in 1968, making it 57 years old in 2025.

What condition is FSR 644 over Rocky Gulch 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 September 2023.

How much traffic does FSR 644 over Rocky Gulch carry?

About 75 vehicles per day (2021 count).

How long is FSR 644 over Rocky Gulch?

The structure is 29 ft (8.7 m) long with a longest span of 28 ft (8.4 m) and a deck 15 ft wide.

Who owns FSR 644 over Rocky Gulch?

It is owned by the U.S. Forest Service.