US Bridges

Brown Trout Lane over Big Thompson River

Good

Larimer County, Colorado · 0.2 MI S of US HWY 34 · Structure no. LRB15-2092BTC

Built
1977
48 years old
Condition
Good
inspected June 2023
Type
Tee Beam
Prestressed Concrete
Length
60 ft
1 main span
Daily traffic
2
2023 count
Owner
County
County Highway Agency

About this bridge

Brown Trout Lane over Big Thompson River is a prestressed concrete tee beam carrying Brown Trout Lane over Big Thompson River in Larimer County, Colorado. It was built in 1977, so it is 48 years old, older than the Colorado average of 42.2 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 2 vehicles a day, projected to reach 2 by 2042. The structure is 60 ft (18.3 m) long and 12 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesBrown Trout Lane
CrossesBig Thompson River
Location0.2 MI S of US HWY 34
RouteCounty Highway 0
CountyLarimer County
StateColorado
Coordinates40.40689, -105.40636
Functional classRural Local

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating36 US tons
Inventory rating18.6 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadH 15
Structure length60 ft (18.3 m)
Longest span58 ft (17.7 m)
Deck width12 ft (3.7 m)
Roadway width11 ft (3.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2 (2023)
Projected traffic2 by 2042
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byOther Local Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$102,000 (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Brown Trout Lane over Big Thompson River built?

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

What condition is Brown Trout Lane over Big Thompson River 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 June 2023.

How much traffic does Brown Trout Lane over Big Thompson River carry?

About 2 vehicles per day (2023 count).

How long is Brown Trout Lane over Big Thompson River?

The structure is 60 ft (18.3 m) long with a longest span of 58 ft (17.7 m) and a deck 12 ft wide.

Who owns Brown Trout Lane over Big Thompson River?

It is owned by the County Highway Agency and maintained by the Other Local Agency.